(Meth)acrylate having an alkenyl group, an epoxy (meth)acrylate, a (meth)acrylic resin having alkenyl groups, a (meth)acrylic resin having epoxy groups, a thermosetting resin composition, a coating composition, a powder coating composition

ABSTRACT

Disclosed are a novel (meth)acrylate having an alkenyl group, a novel epoxy(meth)acrylate, and processes for the preparation thereof. 
     The (meth)acrylate having an alkenyl group of the present invention can be preferably used as resins for coatings, photo-curable resins, and adhesives by (co)polymerization thereof in the presence or absence of a variety of (meth)acrylic monomers, and the (meth)acrylate compound having an alkenyl group is useful as a silane coupling agent, a starting material for epoxy(meth)acrylates, a modifier for silicone resins, a modifier for unsaturated polyester resins, and a crosslinking agent for acrylic rubbers. The epoxy(meth)acrylate has a well-balanced excellent property between a pot life and reactivity in curing, and it does not contain chlorine, resulting in that a resin therefrom is excellent in an anti-corrosive property and an anti-yellowing property. 
     Still further, the present invention relates to a (meth)acrylic resin having alkenyl groups as side chains, a (meth)acrylic resin having epoxy groups as side chains, and processes thereof. 
     In addition, the present invention relates to a thermosetting resin composition, a coating composition and a powder coating composition which have anti-corrosive properties to substrates and anti-yellowing properties in coating layers.

FIELD OF THE INVENTION

The present invention relates to a novel (meth)acrylate having analkenyl group and to a process for the preparation thereof.

The (meth)acrylate having an alkenyl group of the present invention canbe preferably used as resins for coatings, photo-curable resins, andadhesives by (co)polymerization thereof in the presence or absence of avariety of (meth)acrylic monomers, and the (meth)acrylate having analkenyl group is useful as a silane coupling agent, a starting materialfor epoxy (meth)acrylates, a modifier for silicone resins, a modifierfor unsaturated polyester resins, and a crosslinking agent for acrylicrubbers.

Furthermore, the present invention relates to a novelepoxy(meth)acrylate and to a process for the preparation thereof.

The epoxy(meth)acrylate has a well-balanced excellent property between apot-life and reactivity in curing, and it does not contain chlorine,resulting in that a resin therefrom is excellent in an anti-corrosiveproperty and anti-yellowing property. That is, the reactivity of theepoxy(meth)acrylate in cationic polymerization with a cationic catalystis milder than epoxy(meth)acrylates having an alicyclic epoxy group, andquicker epoxy(meth)acrylates having than glycidyl group orbeta-methylglycidyl group.

Furthermore, the reactivity of the epoxy(meth)acrylate with compoundshaving carboxylic group is milder than epoxy(meth)acrylates havingglycidyl group, and quicker than epoxy(meth)acrylates havingbeta-methylglycidyl group.

Still further, the present invention relates to a (meth)acrylic resinhaving alkenyl groups as side chains, a (meth)acrylic resin having epoxygroups as side chains, and processes thereof.

In addition, the present invention relates to a thermosetting resincomposition, and further a coating composition and a powder coatingcomposition which have anti-corrosive properties to substrates andanti-yellowing properties in coating layers.

BACKGROUND OF THE INVENTION

An unsaturated carboxylate having a vinyl group is useful as a startingmaterial for oxidation-curable type coating resins, unsaturatedpolyester resins, photo-curable resins, and silane-coupling agents, andfurther as a crosslinking agent for acrylic rubbers. In these uses,allylmethacrylates are widely employed at the present time.

However double bond in the allylmethacrylates is unstable, resulting inthat there has been a problem of gelling in preparation of polymers ofthe allylmethacrylates and in radical copolymerization with a variety ofacrylic monomers. Furthermore, allyl group is rigid because of fewcarbon numbers, resulting in that resins obtained therefrom do not havesufficient flexibility. Still further, a reaction velocity inhydrosilylation is slow in the case of preparation of silane couplingagents, and unreacted double bonds often remain in the reaction system.

In the meantime, hitherto, there have been used a variety of resincuring systems in coatings, adhesives, and photo-curable resins.

In the resin systems, there is widely employed a curing system in whichthere is employed a (meth)acrylic resin having epoxy groups as sidechains obtained by (co)polymerization of a (meth)acrylate having epoxygroup, owing to exceeding usefulness.

As the (meth)acrylates having epoxy group to be employed in the curingsystem, there are well known glycidyl methacrylate, beta-methylglycidyl(meth)acrylate, 3,4-epoxycyclohexylmethyl(meth)acrylate. For example,Japanese Patent Publication (Kokai) No. 45577/1990 describes a coatingcomposition in which there is employed a curing reaction betweenglycidyl methacrylate and compounds having carboxylic groups.Furthermore, Japanese Patent Publication (Kokai) No. 73825/1990describes a coating composition in which there is employed a cationiccuring reaction of an alicyclic epoxy(meth)acrylate such as3,4-epoxycyclohexylmethyl(meth)acrylate with compounds having silanolgroups.

However, as glycidyl methacrylate has an exceedingly high reactivitywith the compounds having carboxylic group, in the case when it isemployed as a one-liquid type coating composition, a pot-life is short,resulting in causing a problem of gelation. Furthermore, glycidyl groupis slow in curing reaction velocity in the case of the use of cationiccatalysts.

Accordingly, it is substantially difficult to employ glycidylmethacrylate in the curing system described in the Kokai No. 73825/1990.

Still further, alicyclic epoxy groups in the alicyclicepoxy(meth)acrylate such as 3,4-epoxycyclohexylmethyl(meth)acrylate hasa high reactivity in a cationic curing, accordingly, in the case whenthe alicyclic epoxy(meth)acrylate is employed in a coating systemcontaining compounds having carboxylic groups or in the presence ofcatalysts having a relatively strong acidity such as phosphoric acid,oxalic acid, p-toluene sulfonic acid, there is a problem that a pot-lifeis short because a cationic polymerization is caused by hydroxyl groupsin the system which act as an initiator, resulting in that there isdifficult the selection of curing catalysts exhibiting an appropriatepot-life.

On the other hand, beta-methylglycidyl (meth)acrylate has a mildreactivity with compounds having carboxylic groups or in cationiccuring, accordingly, although a pot-life can be lengthened in one-liquidtype coatings, there has been a problem that a curing reaction time ofperiod is lengthened or higher curing temperatures require, resulting inthat a selection range in curing conditions is narrow.

Furthermore, glycidyl (meth)acrylate and beta-methylglycidyl(meth)acrylate contain chlorine even after purification because theseare prepared from epichlorohydrin and beta-methylepichlorohydrin, whichare starting materials, respectively, resulting in that it is not ableto prevent corrosion in substrates and yellowing in coatings during acuring reaction for baking.

For the purpose of solving the above-mentioned disadvantages, as aresult of an intensive investigation, the inventors of this inventionhave now found that it is possible to solve the various problems byresins in which a (meth)acrylate having an alkenyl group and anepoxy(meth)acrylate are (co)polymerized, respectively.

The (meth)acrylate having an alkenyl group of the present invention canprovide a (meth)acrylic resin having alkenyl group-containing sidechains by the (co)polymerization in the presence or absence of a varietyof polymerizable monomers. The (meth)acrylic resin can be employed asresins for curable reactions in coatings, photo-curable resin, andadhesives, etc. As the (meth)acrylic resin contains double bonds as sidechains differently from allylmethacrylate copolymers, it can provide acured article having excellent flexibility. Furthermore the(meth)acrylic resin optionally contains an inner double bond, it canprovide a cured article having an improved crosslinking density.

An epoxy(meth)acrylate of the present invention can provide a(meth)acrylic resin having epoxy group-containing side chains obtainedby the (co)polymerization in the presence or absence of a variety ofpolymerizable monomers. The (meth)acrylic resin has a well-balancedproperty between a pot-life and reactivity in curing, and has ananti-corrosion property to substrates and anti-yellowing property.

The (meth)acrylic resin having epoxy group-containing side chains of thepresent invention can provide a thermosetting resin composition whichcan be employed as a coating composition.

In the case when the thermosetting resin composition of the presentinvention is employed as a coating composition, it can provide a coatinglayer having flexibility because epoxy groups which are crosslinkingpoints are situated at a position separated from the main chain of the(meth)acrylic resin.

In the meantime, for more than ten years, powder coating compositionshave been widely used in many fields, because, e.g., of the followingexcellent properties:

(a) it does not contain any solvents, therefore, it has an advantage ofpresenting less physiological hazards and environmental pollutionhazards, and avoiding the risk of fire;

(b) it requires only reasonable costs, because as mentioned above,solvents are not used, and because excess parts of a powder coatingcomposition which is not fixed onto the substrate to be coated at thetime of application can be recovered completely;

(c) it has a capability of being used to form thick coating layers of upto 100 microns, which cannot be achieved with paints or varnishes havingsolvents;

(d) its coated and cured layer does not tend to soften even when exposedto an elevated temperature atmosphere; and

(e) it has a characteristic of better adhesion to metal substrates.

An acid-curing type powder coating by use of a polybasic acid or acarboxyl-terminated polyester resin having at least 2 carboxylic groupsin a molecule has been widely used because of various kinds of excellentproperties, such as ductility of the coating layer, surface hardness ofthe coating layer, etc., in addition to the above-described (a) to (e).

They can be attained by adjusting the molecular weight and byappropriate selection of a combination of a polycarboxylic acid(s) and apolyhydric alcohol(s), said polyester resin can be readily prepared byan esterification reaction between (n+1) mole of a polycarboxylicacid(s) and n mole of a polyhydric alcohol(s).

A polyester resin having carboxyl groups in terminal positions usuallyreacts with an epoxy resin to form a cured coating layer as describedhereinafter.

Namely, carboxyl groups in terminal positions and epoxy groups react andcure by heating at the presence of catalyst, resulting in formation oftough coating layer.

So-called epi-bis type epoxy resins produced by a reaction betweenbisphenol A and epichlorohydrin, novolak type epoxy resins produced by areaction between a novolak phenol resin and epichlorohydrin and the likehave been used in the above-described curing reaction with a polyesterresin. However, the above-described epoxy resin cannot give sufficientresistance to heat and good outdoor durability to the coated layer madefrom a corresponding powder coating composition.

Furthermore, a powder coating in which a (meth)acrylic resin havingepoxy groups are mixed with a curing agent having carboxylic groups iswidely used because of excellent weatherability and gloss.

Hitherto, glycidyl methacrylate has been widely used as the(meth)acrylic resin having epoxy groups. However, the epoxy group inglycidyl methacrylate has an exceedingly high reactivity with thecompounds having carboxylic group as described hereinabove.

Accordingly, in the case when a (meth)acrylic resin containing glycidylmethacrylate is kneaded with a curing agent and pigments, etc. toprepare a powder coating composition, there were disadvantages that thepowder coating composition is not sufficiently kneaded because of thereaction between epoxy groups and carboxylic groups, and fluidity inmelting for baking is insufficient, resulting in that coating layertherefrom does not exhibit an excellent smoothness.

Furthermore, in the case when a carboxyl-terminated polyester resin isemployed as the curing agent having carboxylic groups, it is poor incompatibility with the (meth)acrylic resin containing glycidylmethacrylate, resulting in that the smoothness in coating layertherefrom is considerably deteriorated and occasionally pinholes arecaused.

In recent years, triglycidyl isocyanurate has been used because a powdercoating composition prepared with it can form a layer having excellentresistance to heat, good outdoor durability, and also smoothness on thesurface of coating layer.

However, triglycidyl isocyanurate has a human toxicity.

Furthermore, there has increasingly been required highly advantageousproperties according to the extension of uses of powder coatingcompositions in various fields.

The (meth)acrylic resin having epoxy group-containing side chains of thepresent invention can also provide a powder coating composition having amilder reactivity than epoxy(meth)acrylates having an alicyclic epoxygroup, and a faster reactivity than epoxy(meth)acrylates having glycidylgroup or beta-methylglycidyl group.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a (meth)acrylatehaving an alkenyl group, an epoxy(meth)acrylate, processes for thepreparation thereof, a (meth)acrylic resin having alkenyl groups as sidechains, a (meth)acrylic resin having epoxy groups as side chains,processes thereof a thermosetting resin composition, a coatingcomposition, and a powder coating composition.

A first aspect of the present invention relates to a (meth)acrylatehaving an alkenyl group represented by general formula (1-1)

    CH.sub.2 ═CR.sup.1 --COOCR.sup.a R.sup.b R.sup.c       ( 1-1)

wherein R¹ is a hydrogen or a methyl group, R^(a), R^(b), and R^(c) areeach independently hydrogen or substituted group represented by generalformula (2-1)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10( 2-1),

at least one of R^(a), R^(b), and R.sup. is not hydrogen, R², R⁶, R⁷,and R¹⁰ are each independently hydrogen or an alkyl group having acarbon number of 1 to 10, R³ is independently hydrogen, or an alkyl,alkenyl or epoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸,and R⁹ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 5, k is an integer of 0 to 30, l is an integer of 0 to 5,m is an integer of 0 to 30, and n is an integer of 1 to 5.

A second aspect of the present invention relates to a process for thepreparation of the (meth)acrylate having an alkenyl group whichcomprises a condensation reaction accompanied by dehydration between(meth)acrylic acid and alcohols represented by general formula (3-1), orthe transesterification of (meth)acrylates with alcohols represented bygeneral formula (3-1)

    HO--CR.sup.a R.sup.b R.sup.c                               ( 3-1)

wherein R^(a), R^(b), and R^(c) are each independently hydrogen orsubstituted group represented by general formula (3-2)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10( 3-2),

at least one of R^(a), R^(b), and R^(c) is not hydrogen, R², R⁶, R⁷, andR¹⁰ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, areeach independently hydrogen or alkyl group having a carbon number of 1to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5.

A third aspect of the present invention relates to anepoxy(meth)acrylate represented by general formula (1-2)

    CH.sub.2 ═CR.sup.1 --COOCR.sup.a' R.sup.b' R.sup.c'    ( 1-2)

wherein R¹ is a hydrogen or a methyl group, R^(a) ', R^(b) 40 , andR^(c) 40 are each an independent hydrogen or substituted grouprepresented by general formula (2-2) ##STR1## at least one of R^(a'),R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰ are eachindependently hydrogen or alkyl group having a carbon number of 1 to 10,R³ is independently hydrogen, or an alkyl, alkenyl or epoxy group havinga carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹ are each independentlyhydrogen or alkyl group having a carbon number of 1 to 5, k is aninteger of 0 to 30, l is an integer of 0 to 5, m is an integer of 0 to30, and n is an integer of 1 to 5.

A fourth aspect of the present invention relates to a process for thepreparation of the epoxy(meth)acrylate.

A fifth aspect of the present invention relates to a (meth)acrylic resinhaving alkenyl group-containing side chains represented by generalformula (1-3)

    --COOCR.sup.a R.sup.b R.sup.c                              ( 1-3)

wherein R^(a), R^(b), and R^(c) are each independently hydrogen orsubstituted group represented by general formula (2-1)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10( 2-1),

at least one of R^(a'), R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷,and R¹⁰ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, areeach independently hydrogen or alkyl group having a carbon number of 1to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5.

A sixth aspect of the present invention relates to a process for thepreparation of the (meth)acrylic resin having alkenyl group-containingside chains.

A seventh aspect of the present invention relates to a (meth)acrylicresin having epoxy group-containing side chains represented by generalformula (1-4), or having the epoxy group-containing side chainsrepresented by the general formula (1-4) and side chains represented bygeneral formula (1-4)'

    --COOCR.sup.a' R.sup.b ' R.sup.c'                          ( 1-4)

    --COOCR.sup.d                                              ( 1-4)'

wherein R^(a'), R^(b'), and R^(c') are each an independent hydrogen orsubstituted group represented by general formula (2-2), R^(d) is afunctional group capable of reacting with epoxy group ##STR2## at leastone of R^(a'), R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰are each independently hydrogen or alkyl group having a carbon number of1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl or epoxygroup having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, are eachindependently hydrogen or alkyl group having a carbon number of 1 to 5,k is an integer of 0 to 30, l is an integer of 0 to 5, m is an integerof 0 to 30, and n is an integer of 1 to 5.

A eighth aspect of the present invention relates to a process for thepreparation of the (meth)acrylic resin having epoxy group-containingside chains.

A ninth aspect of the present invention relates to a thermosetting resincomposition comprising a (meth)acrylic resin having epoxygroup-containing side chains represented by general formula (1-4) andside chains represented by general formula (1-4)'

    --COOCR.sup.a' R.sup.b' R.sup.c'                           ( 1-4)

    --COOCR.sup.d                                              ( 1-4)'

wherein R^(a'), R^(b'), and R^(c') are each an independent hydrogen orsubstituted group represented by general formula (2-2), R^(d) is afunctional group capable of reacting with epoxy group ##STR3## at leastone of R^(a'), R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰are each independently hydrogen, alkyl group having a carbon number of 1to 10, R³ is independently hydrogen, or an alkyl, alkenyl or epoxy grouphaving a carbon number of 1 to 10, R⁴ ₄, R⁵, R⁸ and R⁹, are eachindependently hydrogen or alkyl group having a carbon number of 1 to 5,k is an integer of 0 to 30, l is an integer of 0 to 5, m is an integerof 0 to 30, and n is an integer of 1 to 5 and, optionally a compoundhaving functional groups capable of reacting with an epoxy group.

A tenth aspect of the present invention relates to a coating compositioncontaining the thermosetting resin composition.

A eleventh aspect of the present invention relates to a powder coatingcomposition containing the thermosetting resin composition.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a graph exhibiting respective reactivity of theepoxy(meth)acrylates obtained in Examples 9-12 and 14.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described hereinafter in more detail.

According to a first aspect of the present invention, there is provideda (meth)acrylate having an alkenyl group represented by general formula(1-1)

    CH.sub.2 ═CR.sup.1 --COOCR.sup.a R.sup.b R.sup.c       (1-1)

wherein R¹ is a hydrogen or a methyl group, R^(a), R^(b), and R^(c) areeach independently hydrogen or substituted group represented by generalformula (2-1)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10(2-1),

at least one of R^(a), R^(b), and R^(c) is not hydrogen, R², R⁶, R⁷, andR¹⁰ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, areeach independently hydrogen or alkyl group having a carbon number of 1to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5.

According to a second aspect of the present invention, there is provideda process for the preparation of the (meth)acrylate having an alkenylgroup which comprises a condensation reaction accompanied by dehydrationbetween (meth)acrylic acid and alcohols represented by general formula(3-1), or the transesterification of (meth)acrylates with alcoholsrepresented by general formula (3-1)

    HO--CR.sup.a R.sup.b R.sup.c                               (3-1)

wherein R^(a), R^(b), and R^(c) are each independent hydrogen orsubstituted group represented by general formula (3-2)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10(3-2),

at least one of R^(a), R^(b), and R^(c) is not hydrogen, R², R⁶, R⁷, andR¹⁰ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, areeach independently hydrogen or alkyl group having a carbon number of 1to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5.

The (meth)acrylate having an alkenyl group represented by the generalformula (1-1) of the present invention can be prepared by thecondensation reaction accompanied by dehydration between (meth)acrylicacid and alcohols represented by the general formula (3-1), or thetransesterification of (meth)acrylates with alcohols represented by thegeneral formula (3-1).

The alcohols represented by the general formula (3-1) essentiallycontain at least one unsaturated double bonds in the molecule.

In the general formula (1-1), R¹ is a hydrogen or a methyl group, whichdepends upon the selection of acrylic acid (or acrylates) or methacrylicacid (or methacrylates) as a starting material. Structural unitrepresented by the general formula (2-1) corresponds to a residual groupof the alcohols represented by the general formula (3-1).

In the general formula (3-1), R², R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ areeach independently hydrogen or alkyl group having a carbon number of 1to 10, and preferably hydrogen or an alkyl group having a carbon numberof 1 to 3, particularly, methyl group or vinyl group, R³ isindependently hydrogen, or an alkyl, alkenyl or epoxy group having acarbon number of 1 to 10. In the general formula (3-1), k is an integerof 0 to 30, preferably 0 to 10, l is an integer of 0 to 5, preferably 0to 2, m is an integer of 0 to 30, preferably 0 to 10, and n is aninteger of 1 to 5, preferably 1 to 2, particularly, k+m is preferablynot more than 5.

In the case when k or m exceeds 30, crosslinking density in a curedarticle cannot be increased because of excessively long methylenechains, unpreferably resulting in that mechanical strength becomes poor.Furthermore, in the case when 1 or n exceeds 5, crosslinking density ina cured article is partially increased excessively, unpreferablyresulting in that the cured article becomes rigid and brittle.

As specific examples of the alcohols represented by the general formula(3-1), there is exemplified a compound such as, for example,3-methyl-2-butene-1-ol, 3-methyl-3-butene-1-ol, 2,7-octadienol,7-octene-1-ol, and 1,7-octadiene-3-ol, etc.

As specific examples of the (meth)acrylate represented by the generalformula (1-1) of the present invention, there are exemplified ##STR4##

In the general formulae (4-1) to (8-1), R¹ is a hydrogen or a methylgroup, which depends upon the selection of acrylic acid (or acrylates)or methacrylic acid (or methacrylates) as a starting material.

As specific examples of the (meth)acrylates to be employed as a startingmaterial as well as (meth)acrylic acid, there are exemplifiedmethyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, andbutyl(meth)acrylate.

(meth)acrylic acid or (meth)acrylates are employed in an amount of 0.1to 10.0 mol, preferably 1.0 to 3.0 mol based on 1 mol of the alcoholsfrom a viewpoint of reaction velocity and economy.

In the case when it is below 0.1, although (meth)acrylic acid or(meth)acrylates are effectively converted to a desired product, itunpreferably requires a large amount of energy for the recovery of thealcohols. On the contrary, in the case when it exceeds 10, although itis preferred from a viewpoint of the selectivity and conversion ratio ofalcohols, (meth)acrylic acid or (meth)acrylates is not effectivelyconverted to a desired product, it unpreferably requires a large amountof energy for the recovery of unreacted (meth)acrylic acid or(meth)acrylates.

The condensation reaction accompanied by dehydration or thetransesterification in the present invention is preferably carried outin the presence of catalysts.

The catalysts to be employed include known catalysts for theconventional condensation reaction accompanied by dehydration or thetransesterification.

Specifically, there can be employed organic sulfonic acids such asp-toluene sulfonic acid, metasulfonic acid, and fluorosulfuric acid,inorganic acids such as sulfuric acid, phosphoric acid, and perchloricacid, bases such as sodium alcoholates, lithium hydroxide, aluminumalcoholates, and sodium hydroxide, etc., tin compounds such as stannousoctylate, dibutyltin dilaurate, monobutyltin oxide, and stannouschloride, etc., titanium compounds such as tetrabutyl titanate,tetraethyl titanate, and tetraisopropyl titanate, etc.

Of those, there are preferably employed organic sulfonic acids such asp-toluene sulfonic acid from a viewpoint of reaction velocity.

The catalysts are employed in an amount ranging from 1 ppm to 10%,preferably from 5 ppm to 1.0% based on the total amount of startingmaterials.

In the case when it is below 1 ppm, the reaction velocity becomesunpreferably slow and a yield becomes also low. On the contrary, in thecase when it exceeds 10%, a product unpreferably colors and gelation isunpreferably caused by side reactions.

Although the reaction may be carried out even in the absence ofsolvents, there may be preferably employed a solvent for azeotropicallyremoving water or alcohols which are generated with the progress of thecondensation reaction accompanied by dehydration or thetransesterification, resulting in effectively accelerating the reaction.

As the solvents, there can be employed benzene, toluene, xylene,n-hexane, n-heptane, and methylisobutyl ketone, etc.

The azeotropic solvents are employed in an amount ranging from 0.1 to10-fold, preferably from 2 to 5-fold based on the amount of thereactants. The azeotropic solvents distilled off with water or alcoholscan be circularly employed after separation.

The reaction can be carried out at temperatures ranging from 65° to 150°C., preferably from 75° to 120° C. from a viewpoint of reducing thereaction period of time and preventing polymerization.

In the case when it is below 65° C., the reaction velocity isexcessively slow, resulting in low yield. On the contrary, in the casewhen it exceeds 150°C., (meth)acrylic acid, (meth)acrylates, and theresulting (meth)acrylates having alkenyl group unpreferably thermallypolymerize.

The reaction can be preferably carried out in the presence ofpolymerization inhibitors as well as streaming air in order to preventthe thermal polymerization of (meth)acrylic acid, (meth)acrylates, andthe resulting (meth)acrylates having alkenyl group unpreferablythermally polymerize.

As the polymerization inhibitors, there can be employed hydroquinone,hydroquinone monomethylether, p-methoxyphenol,2,4-dimethyl-6-t-butylphenol, 3-hydroxythiophenol,alpha-nitroso-beta-naphtol, p-benzoquinone, 2,5-dihydroxy-p-quinone, andcopper salts, etc.

Of those, there can be preferably employed hydroquinone andp-methoxyphenol from a viewpoint of stability.

The polymerization inhibitors are employed in an amount of 0.001 to5.0%, preferably 0.01 to 1.0% based on the amount of (meth)acrylic acidor (meth)acrylates which are starting materials. In the case when it isbelow 0.001%, effectiveness as the polymerization inhibitors is minor.On the contrary, even in the case when it exceeds 5%, the effectivenessdoes not increase, resulting in only becoming uneconomical.

The reaction is preferably carried out in ordinary pressures or slightlyreduced pressure conditions.

A reaction crude solution obtained in the condensation reaction ortransesterification contains unreacted (meth)acrylic acid or(meth)acrylates. Accordingly, the solution is preferably washed withwater, or low-boiling-point ingredients are preferably removed afterneutralization with an aqueous alkali solution. There may be employedaqueous alkali solution containing NaOH, KOH, K₂ CO₃, Na₂ CO₃, NaHCO₃,KHCO₃, and NH₃, etc.

The aqueous alkali solution can be employed in a wide range of theconcentration. Water washing is preferably carried out afterneutralization in order to prevent residue of neutralized salts in aproduct. The removal of the low boiling point ingredients is preferablycarried out with a thin-layer evaporator, etc. after neutralization andwater washing.

According to a third aspect of the present invention, there is providedan epoxy(meth)acrylate represented by general formula (1-2)

    CH.sub.2 ═CR.sup.1 --COOCR.sup.a' R.sup.b' R.sup.c'    (1-2)

wherein R¹ is a hydrogen or a methyl group, R^(a'), R^(b'), and R^(c')are each an independent hydrogen or substituted group represented bygeneral formula (2-2) ##STR5## at least one of R^(a'), R^(b'), andR^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰ are each independentlyhydrogen or alkyl group having a carbon number of 1 to 10, R³ isindependently hydrogen, or an alkyl, alkenyl or epoxy group having acarbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹ are each independentlyhydrogen or alkyl group having a carbon number of 1 to 5, k is aninteger of 0 to 30, l is an integer of 0 to 5, m is an integer of 0 to30, and n is an integer of 1 to 5.

According to a fourth aspect of the present invention, there is provideda process for the preparation of the epoxy(meth)acrylate.

The epoxy(meth)acrylate represented by the general formula (1-2) areprepared by the epoxidation of the (meth)acrylate represented by generalformula (1-1) of the first aspect described hereinabove with anepoxidation agent.

Accordingly, in the formula (1-2), R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹,R¹⁰, k, l, m, and n are all the same as in the formula (1-1).

As the epoxidation agent to be employed, there are exemplified organicperacids such as performic acid, peracetic acid, perpropionic acid,m-chloroperbenzoic acid, trifluoroperacetic acid, perbenzoic acid, etc.,hydroperoxides such as t-butylhydroperoxide, cumylhydroperoxide,tetrallyl-hydroperoxide, diisopropylbenzenehydroperoxide, and hydrogenperoxide, etc.

The epoxidation agent is employed in a ratio of from 0.1 to 10 mol,preferably from 0.5 to 2 mol, more preferably from 0.8 to 1.2 mol basedon 1 mol of alkenyl group in the (meth)acrylate represented by generalformula (1-1).

In the case when the ratio exceeds 10, the (meth)acrylate represented bygeneral formula (1-1) is preferably converted to theepoxy(meth)acrylate, and the reaction period can be preferablyshortened, resulting in reduction of the loss of the (meth)acrylate bythe polymerization.

However, side reactions occur by excessive amounts of the epoxidationagent and the selectivity of the epoxidation agent lowers, and furtherit unpreferably requires large amounts of costs for recovery of theunreacted epoxidation agent. On the contrary, in the case when the ratiois below 0.1, although the epoxidation agent is selectively convertedand side reactions are preferably prevented, the (meth)acrylateunpreferably polymerize, resulting in increasing the loss of the(meth)acrylate, and further it unpreferably requires large amounts ofcosts for recovery of the unreacted (meth)acrylate.

The epoxidation reaction is carried out in a temperature range of 0° to150° C., more specifically, less than the maximum temperature in whichepoxidation reaction more predominantly causes than decompositionreaction of the epoxidation agents. For example, in the case whenperacetic acid is employed, it is less than 70° C., and in the case whent-butylhydroperoxide is employed, it is less than 150° C. When thereaction temperature is low, there requires a long time of period forcompletion of the reaction.

In the case of peracetic acid, the minimum temperature is preferably 0°C., and in the case of t-butylhydroperoxide, the minimum temperature ispreferably 20° C.

Although the reaction may be carried out even in the absence ofsolvents, there may be preferably employed solvents such as benzene,toluene, and xylene, etc. which are aromatic solvents, chloroform,dimethylchloride, carbon tetrachloride, and chlorobenzene, etc. whichare halogenated solvents, ethyl acetate and butylacetate, etc. which areester compounds, acetone and methylisobutyl ketone, etc. which areketone compounds, 1,2-dimethoxy ethane, etc. which is an ether compound.

The epoxidation reaction can be preferably carried out in the presenceof polymerization inhibitors in order to prevent the thermally radicalpolymerization of the starting (meth)acrylates.

As the polymerization inhibitors, there are employed hydroquinone,hydroquinone monomethylether, p-methoxyphenol,2,4-dimethyl-6-t-butylphenol, 3-hydroxythiophenol,alpha-nitroso-beta-naphtol, p-benzoquinone, 2,5-dihydroxy-p-quinone, andcopper salts, etc. Of those, there are preferably employed hydroquinoneand p-methoxyphenol from a viewpoint of stability.

The polymerization inhibitors are employed in an amount of 0.001 to5.0%, preferably 0.01 to 1.0% based on the amount of starting(meth)acrylates. In the case when it is below 0.001%, effectiveness asthe polymerization inhibitors is minor. On the contrary, even in thecase when it exceeds 5%, effectiveness does not increase, resulting inbecoming uneconomical. The polymerization inhibitors are preferablydissolved in the starting (meth)acrylates before the epoxidationreaction.

Furthermore, the epoxidation reaction can be preferably carried out inthe presence of air in order to prevent the thermally radicalpolymerization of the starting (meth)acrylates.

A reaction crude solution obtained in the epoxidation reaction ispreferably washed with water or low boiling point ingredients arepreferably removed after neutralization with an aqueous alkali solution.

There may be employed aqueous alkali solution containing NaOH, KOH, K₂CO₃, Na₂ CO₃, NaHCO₃, KHCO₃, and NH₃, etc.

The aqueous alkali solution can be employed in a wide range of theconcentration. Water washing is preferably carried out afterneutralization in order to prevent residue of neutralized salts in aproduct. The removal of the low-boiling-point ingredients is preferablycarried out with a thin layer evaporator, etc. after neutralization andwater washing.

According to a fifth aspect of the present invention, there is provideda (meth)acrylic resin having alkenyl group-containing side chainsrepresented by general formula (1-3)

    --COOCR.sup.a R.sup.b R.sup.c                              (1-3)

wherein R^(a), R^(b), and R^(c) are each independently hydrogen orsubstituted group represented by general formula (2-1)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10(2-1),

at least one of R^(a), R^(b), and R^(c) is not hydrogen, R², R⁶, R⁷, andR¹⁰ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, areeach independently hydrogen or alkyl group having a carbon number of 1to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5.

According to a sixth aspect of the present invention, there is provideda process for the preparation of the (meth)acrylic resin having alkenylgroup-containing side chains represented by general formula (1-3)comprising the radical (co)polymerization of the (meth)acrylate havingalkenyl group represented by general formula (1-1) in the presence orabsence of a monomer having an unsaturated double bond.

The (meth)acrylic resin having alkenyl group-containing side chainsrepresented by general formula (1-3) of the present invention can beprepared by the radical (co)polymerization of the (meth)acrylate havingalkenyl group represented by general formula (1-1) in the presence orabsence of a polymerizable monomer having an unsaturated double bond.

As the polymerizable monomer having an unsaturated double bond, therecan be employed a variety of monomers which are employed in processesfor the preparation of the conventional (meth)acrylic resins, whichspecifically include vinyl monomers such as styrene, 2-methyl styrene,vinyl acetate, and vinyl chloride, etc., (meth)acrylic acid,(meth)acrylates such as methyl(meth)acrylate, propyl(meth)acrylate,butyl(meth)acrylate, pentyl(meth)acrylate, and hexyl(meth)acrylate,(meth)acrylates having hydroxylic group such as2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,2-hydroxybutyl(meth)acrylate, a lactone-modified2-hydroxyethyl(meth)acrylate, etc. Furthermore, there can be alsoemployed (meth)acrylates such as methoxy diethyleneglycol(meth)acrylate,ethoxydiethyleneglycol(meth)acrylate,isooctyloxydiethyleneglycol(meth)acrylate,phenoxytriethyleneglycol(meth)acrylate,methoxytriethyleneglycol(meth)acrylate,methoxypolyethyleneglycol(meth)acrylate, (meth)acrylates having aterminated silane or silyl group such as 2-trimethylsiloxaneethyl(meth)acrylate, (meth)acrylates having a terminated epoxy groupsuch as glycidyl(meth)acrylate and3,4-epoxycyclohexylmethyl(meth)acrylate, unsaturateddicarboxylic acidssuch as maleic anhydride and derivatives thereof, etc.

At least one of the monomers may be employed.

The (meth)acrylic resin having alkenyl group-containing side chainsrepresented by the general formula (1-3) of the present invention can begiven a variety of properties by the wide selection of theabove-described polymerizable monomers.

For example, in the case when (meth)acrylic acid is copolymerized withthe (meth)acrylate having alkenyl group represented by the generalformula (1-1), a resulting (meth)acrylic resin has double bonds andcarboxylic groups as side chains, which can be employed as a resin foralkali-developing type photo-resists.

Furthermore, the (meth)acrylic resin having alkenyl group-containingside chains of the present invention can be employed as a thermosettingresin by hydrosilylation reaction because of the double bonds in theside chains.

In the case when the (meth)acrylate having alkenyl group represented bythe general formula (1-1) is copolymerized with the above-describedpolymerizable monomers, there is preferably selected a mixing ratio inwhich the concentration of double bonds at side chains in the(meth)acrylic resin having alkenyl group-containing side chainsrepresented by general formula (1-3) ranges from 0.5 to 7.0 mol/kg, andpreferably from 1.3 to 3.4 mol/kg.

In the case when it exceeds 7.0 mol/kg, gelation is readily caused inthe copolymerization. On the contrary, in the case when it is below 0.5mol/kg, although the copolymerization readily proceeds, there are notincluded large amounts of ethylenic double bonds in the (meth)acrylicresin obtained which are necessary for forming crosslinking structuresby photo or thermal energy, resulting in that industrial worth of theresin considerably decreases.

It is to be noted that also in the case when the (meth)acrylate havingalkenyl group represented by the general formula (1-1) alone ispolymerized, there is preferably selected the concentration of doublebonds at side chains which ranges from 0.5 to 7.0 mol/kg, and preferablyfrom 1.3 to 3.4 mol/kg by the selection or combination of the alcoholsrepresented by general formula (3-1).

The radical (co)polymerization of the (meth)acrylate having alkenylgroup is carried out by conventional methods such as, for example,emulsion polymerization, suspension polymerization, solutionpolymerization, and bulk polymerization. Of those, solutionpolymerization in which solvents are employed is preferably carried outfrom a viewpoint of preventing gelation and capability of homogeneousreaction.

In the case of solution polymerization, solvents are employed in anamount ranging from 0 to 95% by weight, preferably from 60 to 90% byweight based on the total amounts of the monomers.

In the case when it exceeds 95% by weight, although the polymerizationis readily carried out, it becomes disadvantageous from a viewpoint offactors concerning productivity such as recovery of the solvents and aplant scale.

The radical (co)polymerization of the (meth)acrylate having alkenylgroup in the present invention is carried out in a temperature range ofapproximately from 30° to 120° C., preferably from 50° to 100° C., whichis a temperature range for carrying out conventional radical(co)polymerization.

As the solvents, there may be preferably employed one or more ofsolvents such as benzene, toluene, and xylene, etc. which are aromaticsolvents, methanol, ethanol, and 2-propanol which are alcohols, acetone,methylethyl ketone, and methylisobutyl ketone, etc. which are ketonecompounds, diethylether, dibutyl ether, dioxane, etc. which are ethercompounds, ethyl acetate, isobutyl acetate, ethyleneglycol monoacetate,and propyleneglycol monoalkyl acetate, etc. which are ester compounds,dimethylformamide and dimethylacetoamide which are amides, chloroform,dimethylchloride, carbon tetrachloride, and chlorobenzene, etc. whichare halogenated solvents, etc.

The radical (co)polymerization of the (meth)acrylate having alkenylgroup in the present invention is carried out in the presence of one ormore of conventional polymerization initiators such as2,2'-azobisisobutylnitrile and 2,2'-azobis(2,4-dimethylvaleronitrile)which are azobis-based initiators, lauroyl peroxide, di-t-butylperoxide,bis(4-t-butylcyclohexyl)peroxydicarbonate,t-butylperoxy(2-ethylhexanoate), methylethylketone peroxide, and benzoylperoxide, etc. which are peroxides.

According to a seventh aspect of the present invention, there isprovided a (meth)acrylic resin having epoxy group-containing side chainsrepresented by general formula (1-4), or having the epoxygroup-containing side chains represented by general formula (1-4) andside chains represented by general formula (1-4)'

    --COOCR.sup.a' R.sup.b' R.sup.c'                           (1-4)

    --COOCR.sup.d                                              (1-4)'

wherein R^(a'), R^(b'), and R^(c') are each an independent hydrogen orsubstituted group represented by general formula (2-2), R^(d) is afunctional group capable of reacting with epoxy group ##STR6## at leastone of R^(a'), R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰are each independently hydrogen or alkyl group having a carbon number of1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl or epoxygroup having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, are eachindependently hydrogen or alkyl group having a carbon number of 1 to 5,k is an integer of 0 to 30, l is an integer of 0 to 5, m is an integerof 0 to 30, and n is an integer of 1 to 5.

According to an eighth aspect of the present invention, there isprovided a process for the preparation of the (meth)acrylic resin havingepoxy group-containing side chains comprising the radical(co)polymerization of the epoxy(meth)acrylate represented by the generalformula (1-2) in the presence or absence of a monomer having anunsaturated double bond.

As the monomer having an unsaturated double bond, there are employed avariety of monomers which are employed in processes of the conventional(meth)acrylic resins, which specifically include vinyl monomers such asstyrene, 2-methyl styrene, vinyl acetate, and vinyl chloride, vinylidenechloride, vinyl fluoride, vinylidene fluoride, butadiene, isoprene,etc., monomers having carboxylic group such as (meth)acrylic acid,crotonic acid, itaconic acid, maleic acid, fumaric acid, (meth)acrylatessuch as methyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate,pentyl(meth)acrylate, and hexyl(meth)acrylate, (meth)acrylates havinghydroxylic group such as 2-hydroxyethyl(meth)acrylate,2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, alactone-modified 2-hydroxyethyl(meth)acrylate (for example, PCL-FA andPCL-FM, etc., manufactured by Daicel Chemical Industries, Ltd.), etc.,monomers having hydroxylic group such as allyl alcohol and mathallylalcohol, etc., monomers having amino group such asdimethylaminoethyl(meth)acrylate, monomers having amide group such as(meth)acrylic amide, monomers having nitrile group such as(meth)acrylonitrile, (meth)acrylates such as methoxy diethyleneglycol(meth)acrylate, ethoxydiethyleneglycol (meth)acrylate,isooctyloxydiethyleneglycol (meth)acrylate, phenoxytriethyleneglycol(meth)acrylate, methoxytriethyleneglycol (meth)acrylate,methoxypolyethyl-eneglycol (meth)acrylate, (meth)acrylates having aterminated silane or silyl group such as 2-trimethylsiloxane ethyl(meth)acrylate, (meth)acrylates having a terminated epoxy group such asglycidyl methacrylate and 3,4-epoxycyclohexyl-methyl (meth)acrylate,unsaturated dicarboxylic acids such as maleic anhydride and derivativesthereof, etc. At least one of the monomers may be employed.

The radical (co)polymerization of the epoxy(meth)acrylate represented bythe general formula (1-2) in the present invention is preferably carriedout in the presence of one or more of conventional polymerizationinitiators such as 2,2'-azobisisobutylnitrile and 2,2'-azobis(2,4-dimethylvaleronitrile) which are organic azobis-based initiators,lauroyl peroxide, cumen hydroperoxide, and di-t-butylperoxide,methylethylketone peroxide, and benzoyl peroxide, etc. which areperoxides, bis(4-t-butyl-cyclohexyl)peroxydicarbonate, andt-butylperoxy(2-ethylhexanoate), potassium persulfate, ammoniumpersulfate, sodium persulfate, hydrogen peroxide, which are inorganicwater-soluble radical initiators, and redox-initiators.

Furthermore, there can be also employed chain transfer agents in theradical (co)polymerization of the epoxy(meth)acrylate represented by thegeneral formula (1-2) in the present invention.

As the chain transfer agents, there are specifically exemplifiedmercaptans such as ethylmercaptan and methylmercaptan,alpha-methylstyrene dimer, halogenated hydrocarbons such as carbontetrachloride and carbon tetrabromide.

The radical (co)polymerization of the epoxy(meth)acrylate is carried outby conventional methods such as, for example, emulsion polymerization,suspension polymerization, solution polymerization, and bulkpolymerization. Of those, solution polymerization in which solvents areemployed is preferably carried out from a viewpoint of preventinggelation and capability of homogeneous reaction.

The radical (co)polymerization of the epoxy(meth)acrylate in the presentinvention is carried out in a temperature range of approximately from30° to 120° C., preferably from 50° to 100° C., which is a temperaturerange for carrying out conventional radical (co)polymerization.

As the solvents in the solution polymerization, there may be preferablyemployed one or more of solvents such as benzene, toluene, and xylene,etc. which are aromatic solvents, methanol, ethanol, and 2-propanolwhich are alcohols, acetone, methylethyl ketone, and methylisobutylketone, etc. which are ketone compounds, diethylether, dibutyl ether,dioxane, etc. which are ether compounds, ethyl acetate, isobutylacetate, ethyleneglycol monoacetate, and propyleneglycol monoalkylacetate, etc. which are ester compounds, dimethylformamide anddimethylacetoamide which are amides, chloroform, dimethylchloride,carbon tetrachloride, and chlorobenzen, etc. which are halogenatedsolvents, etc.

In the case of solution polymerization, solvents are employed in anamount ranging from 0 to 95% by weight, preferably from 60 to 90% byweight based on the total amounts of the monomers.

In the case when it exceeds 95% by weight, although the polymerizationis readily carried out, it becomes disadvantageous from a viewpoint offactors concerning productivity such as recovery of the solvents andplant scale.

Thus-obtained (meth)acrylic resin having epoxy group-containing sidechains represented by the general formula (1-4) of the present inventionis a composition containing a variety of random resin components, andthe average molecular weight ranges generally from 500 to 300,000,preferably from 1,000 to 10,000. Furthermore, oxirane oxygenconcentration in the resin composition ranges generally from 0.5 to 10%by weight, preferably from 1.0 to 5.0% by weight.

It is to be noted that side chains represented by the general formula(1-4)' are described hereinafter, specifically, in a thermosetting resincomposition which is a ninth aspect of the present invention.

According to a ninth aspect of the present invention, there is provideda thermosetting resin composition comprising a (meth)acrylic resinhaving epoxy group-containing side chains represented by general formula(1-4) and side chains represented by general formula (1-4)'

    --COOCR.sup.a' R.sup.b' R.sup.c'                           (1-4)

    --COOCR.sup.d                                              (1-4)'

wherein R^(a'), R^(b'), and R^(c') are each an independent hydrogen orsubstituted group represented by general formula (2-2), R^(d) is afunctional group capable of reacting with epoxy group ##STR7## at leastone of R^(a'), R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰are each independently hydrogen or alkyl group having a carbon number of1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl or epoxygroup having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, are eachindependently hydrogen or alkyl group having a carbon number of 1 to 5,k is an integer of 0 to 30, l is an integer of 0 to 5, m is an integerof 0 to 30, and n is an integer of 1 to 5, and optionally a compoundhaving functional groups capable of reacting with an epoxy group.

According to a tenth aspect of the present invention, there is provideda coating composition containing the thermosetting resin composition.

The thermosetting resin composition of the present invention can beprepared by copolymerization of the epoxy(meth)acrylate represented bythe above general formula (1-2) with a polymerizable monomer having afunctional group represented by general formula (1-4)' which is capableof reacting with an epoxy group.

Furthermore, the thermosetting resin composition of the presentinvention can be also prepared by only mixing the (meth)acrylic resinhaving epoxy group-containing side chains represented by the abovegeneral formula (1-4) which is the fourth aspect of the presentinvention with a compound having functional groups capable of reactingwith an epoxy group.

In the case of mixing with a compound having functional groups capableof reacting with an epoxy group, the side chains represented by theabove-described general formula (1-4)' are not always essential in the(meth)acrylic resin.

Still further, the thermosetting resin composition of the presentinvention can be also prepared by mixing the (meth)acrylic resin havingepoxy group-containing side chains represented by the above generalformula (1-4) with a resin obtained by (co)polymerization of apolymerizable monomer having a functional group represented by generalformula (1-4)' which is capable of reacting with an epoxy group.

Also in the case of mixing with the resin obtained by (co)polymerizationof a polymerizable monomer having a functional group represented bygeneral formula (1-4)', the side chains represented by theabove-described general formula (1-4)' are not always essential in the(meth)acrylic resin.

As practical examples of the functional groups capable of reacting withan epoxy group, there are preferably exemplified carboxylic group,silanol group, hydrolyzable alkoxysilane group, and hydroxyl group.

In the case when the thermosetting resin composition of the presentinvention is employed as a coating composition, it can be employed as aone-component type or two-component type product.

In the following, there is described a method for introducing thefunctional groups capable of reacting with an epoxy group into the(meth)acrylic resin having epoxy group-containing side chainsrepresented by the above general formula (1-4).

As the polymerizable monomer to be employed in order to introducecarboxylic groups, there are employed a variety of monomers which areemployed in processes of the conventional resins having carboxylicgroups, which specifically include monomers having carboxylic group suchas acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconicacid, crotonic acid, a half ester thereof in which anhydride thereof isreacted with an alcohol. In addition to the use of the polymerizablemonomers having carboxylic group, a polymer obtained by copolymerizationof an unsaturated carboxylic anhydride with other monomers which arestarting monomers for preparation of acrylic resins may be also changedto a half ester with an alcohol or a resin having hydroxyl groups.

Furthermore, there can be employed beta-hydroxyalkyl(meth)acrylate suchas 2-hydroxyethyl-(meth)acrylate, 2-hydroxypropyl(meth)acrylate,4-hydroxybutyl(meth)acrylate, a lactone adduct thereof (for example,PCL-FA and PCL-FM, etc., manufactured by Daicel Chemical Industries,Ltd.), etc., and further polymerizable monomers such as an ethyleneoxideor propyleneoxide adducts of (meth)acrylic acid (Blemmer PP and BlemmerPE manufactured by Nihon Yushi, Ltd.) which are monomers havingcarboxylic group at terminal obtained by adding acid anhydrides topolymerizable monomers having hydroxyl group.

As the acid anhydride, there are exemplified succinic anhydride,phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalicanhydride, trimellitic anhydride, a head acid (a derivative havingchlorine of phthalic anhydride), hymic anhydride, adipic anhydride,azelaic anhydride, sebacic anhydride, and derivatives thereof.

The monomers having carboxylic group can be readily prepared by heatingthe polymerizable monomers having hydroxyl group with the acidanhydrides at 60° to 150° C. in the presence of a polymerizationinitiator.

As components in thermosetting resin composition of the presentinvention, there are preferably contained 1 to 80% by weight of theepoxy(meth)acrylate represented by the general formula (1-2) and 5 to60% by weight of the monomers having carboxylic group in the(meth)acrylic resin having epoxy group-containing side chainsrepresented by the general formula (1-4).

The molar ratio of epoxy groups to carboxylic groups generally rangesfrom 1/0.01 to 1/100, preferably from 1/0.1 to 1/10.

Furthermore, the thermosetting resin composition of the presentinvention may contain catalysts for the reaction between epoxy groupsand carboxylic groups.

As specific examples of the catalysts, there are exemplified quaternaryammonium salts such as benzylethyl ammonium chloride or bromide,tetramethyl ammonium chloride or bromide, tin-based catalysts such asdimethyltin bis(methylmaleate), dimethyltin bis(ethylmaleate),dimethyltin bis(butylmaleate), dibutyltin bis(butylmaleate), phosphoruscompounds such as triphenyl phosphine, tetraphenyl phosphonium chlorideor bromide.

The catalysts are employed in an amount ranging from 1 ppm to 1%,preferably from 10 ppm to 3,000 ppm based on the total weight of the(meth)acrylic resin having epoxy group-containing side chainsrepresented by the general formula (1-4).

In the following, there is described a process for introducing hydroxylgroup which is one of the functional groups capable of reacting with anepoxy group.

The epoxy group in the substituted group represented by the generalformula (2-2) can be cured with cationic polymerization catalystsbecause of a high reactivity in a cationic polymerization compared toconventional compounds having glycidyl group such asglycidylmethacrylate.

As monomers for introducing hydroxyl groups which are one of thefunctional groups capable of reacting with an epoxy group, there areexemplified a beta-hydroxyalkyl (meth)acrylate such as2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl-(meth)acrylate,4-hydroxybutyl (meth)acrylate, a lactone adduct thereof (for example,PCL-FA and PCL-FM, etc., manufactured by Daicel Chemical Industries,Ltd.), etc., and further polymerizable monomers such as an ethyleneoxideor propyleneoxide adducts of (meth)acrylic acid (Blemmer PP and BlemmerPE manufactured by Nihon Yushi, Ltd.).

Furthermore, the thermosetting resin composition of the presentinvention may preferably contain conventional amine-based, alkali-basedand acid-based catalysts for the reaction between epoxy groups andhydroxyl groups.

As specific examples of the alkali-based catalysts, there areexemplified imidazoles such as 4-methylimidazole, tertiary amines suchas tris(dimethylamino)phenol, N,N-dimethylbenzylamine, inorganic alkalissuch as KOH and NaOH, alcoholates such as sodium alcoholates.

As specific examples of the acid-based catalysts, there are exemplifiedphosphoric acid or esters thereof, (meth)acrylates having acidicphosphoric acid groups, oxalic acid, succinic acid, trimellitic acid,and p-toluene sulfonic acid which have high acidity and accelerate thecationic polymerization reaction.

The catalysts are employed in an amount ranging from 1 ppm to 10%,preferably from 10 ppm to 2% based on the total weight of the(meth)acrylic resin having epoxy group-containing side chainsrepresented by the general formula (1-4). In the case when it is below 1ppm, acceleration effect in curing is small, and in the case when itexceeds 10%, properties in cured articles unpreferably decrease.

As components in thermo setting resin composition of the presentinvention, there are preferably contained 1 to 80% by weight of theepoxy(meth)acrylate represented by the general formula (1-2) and 5 to60% by weight of the monomers having hydroxyl group in the (meth)acrylicresin having epoxy group-containing side chains represented by thegeneral formula (1-4).

The molar ratio of epoxy groups to hydroxyl groups generally ranges from1/0.01 to 1/100, preferably from 1/0.1 to 1/10.

Furthermore, in the thermosetting resin composition of the presentinvention, compounds having silanol group or hydrolyzable alkoxysilylgroup are preferably employed together with other monomers, resulting inbeing capable of improving properties in cured articles.

As specific examples of compounds having hydrolyzable alkoxysilyl group,there are exemplified the compounds having silanol group or hydrolyzablealkoxysilyl group, silane coupling agents such asbeta-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, and gamma-glycidoxypropylmethyl diethoxysilane, whichact as crosslinking components.

Furthermore, alkoxysilyl group can be also introduced into thethermosetting resin composition of the present invention using resinsobtained by (co)polymerization of a monomer having alkoxysilyl grouprepresented by general formula (4-1)

    CH.sub.2 ═CR.sup.1 --A--R.sup.2 --(SiR.sup.3 R.sup.4 O).sub.n --R.sup.5(4-1)

which is described later.

The resins or compounds having hydrolyzable alkoxysilyl groups arepreferably introduced in a weight ratio of 5 to 50% by weight based onthe total weight of the (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4).

In the following, there is described a process for introducing silanolgroup or hydrolyzable alkoxysilyl group which is one of the functionalgroups capable of reacting with an epoxy group into the (meth)acrylicresin having epoxy group-containing side chains represented by thegeneral formula (1-4).

The epoxy group in the substituted group represented by the generalformula (2-2) can be cured by silanol group or hydrolyzable alkoxysilylgroup with cationic polymerization catalysts because of a highreactivity in a cationic polymerization compared to conventionalcompounds having glycidyl group such as glycidyl methacrylate.

As polymerizable monomers to be employed for introducing silanol groupor hydrolyzable alkoxysilyl group, there are employed the compoundshaving alkoxysilyl group represented by general formula (4-1)

    CH.sub.2 ═CR.sup.1 --A--R.sup.2 --(SiR.sup.3 R.sup.4 O).sub.n --R.sup.5(4-1)

wherein R¹ is hydrogen or methyl group, --A-- is --COO-- or --COO-- C₆H₄ --, R² is a divalent aliphatic hydrocarbon residual group having acarbon number of 1 to 6, R³ and R⁴ is independently phenyl group, alkylgroup having a carbon number of 1 to 6, alkoxyl group having a carbonnumber of 1 to 6, and hydroxyl group, R⁵ is hydrogen, phenyl group,alkyl group having a carbon number of 1 to 6, and alkoxyl group having acarbon number of 1 to 6, n is an integer of 1 to 20, and the unit--(SiR³ R⁴ O)_(n) -- also includes a structure in which silicone isthree-dimensionally extended by siloxane bonds.

Specifically, there are employed gamma-(meth)acryloxypropyltrimethoxysilane, gamma-(meth)acryloxypropyl triethoxysilane,gamma-(meth)acryl-oxypropyl tripropoxysilane,gamma-(meth)acryloxypropylmethyl dimethoxysilane,gamma-(meth)acryloxypropylmethyl diethoxysilane,gamma-(meth)acryloxypropylmethyl dipropoxysilane,gamma-(meth)acryloxybutylphenyl dimethoxysilane,gamma-(meth)acryloxybutylphenyl diethoxysilane,gamma-(meth)acryloxybutylphenyl dipropoxysilane,gamma-(meth)acryloxyproyldimethyl methoxysilane,gamma-(meth)acryloxyproyldimethyl ethoxysilane,gamma-(meth)acryloxyproylphenylmethyl methoxysilane,gamma-(meth)acryloxyproylphenylmethyl ethoxysilane.

Furthermore, there are employed the following compounds ##STR8## whereinR¹ is a hydrogen or an alkyl group having carbon number of 1 to 6.

Of the compounds having alkoxysilyl group represented by the generalformula (4-1), as compounds having carbonyloxyphenylene group in theunit --A--, there are exemplified the following compounds ##STR9##wherein R¹ is a hydrogen or an alkyl group having carbon number of 1 to6.

In the thermosetting resin composition of the present invention, thecompounds having silanol group or hydrolyzable alkoxysilyl group isintroduced into the (meth)acrylic resin having epoxy group-containingside chains represented by the general formula (1-3) in the ratio of1/0.1 to 1/1000, preferably from 1/0.25 to 1/100 with respect to theepoxy(meth)acrylate represented by the general formula (1-2).

In the case when the ratio of the epoxy(meth)acrylate represented by thegeneral formula (1-2) exceeds 1000, curability of the compositiondecreases, and in the case when it is below 0.1, properties in curedarticles and curing velocity decrease, and shrinkage in the curedarticles occasionally is caused.

In the thermosetting resin composition of the present invention, theremay be employed conventional catalysts such as aluminum chelatecompounds, titanium chelate compounds, and zirconium chelate compoundsin order to accelerate the cationic polymerization reaction betweenepoxy groups and silanol groups or hydrolyzable alkoxysilanol groups inthe (meth)acrylic resin having epoxy group-containing side chainsrepresented by the general formula (1-3). The chelate compounds can givean appropriate pot-life.

Of the chelate compounds, there are preferred chelate compounds having acompound capable of forming a keto or enol tautomer as ligand forming astable chelate ring.

As the compounds capable of forming the keto or enol tautomer, there canbe employed beta-diketones such as acetylacetone, acetoacetic acidesters such as methyl acetoacetate, malonic acid esters such as ethylmaloate, ketones having hydroxyl group at beta position such asdiacetonealcohol, aldehydes having hydroxyl group at beta position suchas salicyclic aldehyde, and esters having hydroxyl group at betaposition such as methyl salicylate, etc. Of those, acetoacetic acidesters and beta-diketones are preferred.

Aluminum chelate compounds can be prepared by mixing 1 mol of analuminum alcoholate represented by R--O--Al(OR)--O--R wherein R is analkyl group or alkenyl group having a carbon number of 1 to 20 which maybe identical or different from each other! with approximately 3 mol orless of the compound capable of forming the above-described keto or enoltautomer, optionally followed by heating.

As the aluminum alcoholate represented by R--O--Al(OR)--O--R, there areexemplified aluminum trimethoxide, aluminum trietho-xide, aluminumtri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide,aluminum tri-n-isobutoxide, aluminum tri-sec-butoxide, and aluminumtri-tert-butoxide, etc. Of those, there are preferred aluminumtriisopropoxide, aluminum tri-sec-butoxide, and aluminum tri-n-butoxide.

Titanium chelate compounds can be prepared by mixing 1 mol of antitanium alcoholate represented by R--O-- Ti(OR)₂ --O!_(m) --Ti(OR)₂--OR wherein R is an alkyl group or alkenyl group having a carbon numberof 1 to 20 which may be identical or different from each other, and m isan integer of 0 to 20! with approximately 3 mol or less of the compoundcapable of forming the above-described keto or enol tautomer, optionallyfollowed by heating.

As the titanium alcoholate represented by R--O-- Ti(OR)₂ --O!_(m)--Ti(OR)₂ --OR, there are exemplified tetramethyltitanate,tetraethyltitanate, tetra-n-propyltitanate, tetraisoproyltitanate,tetra-n-butyltitanate, tetraisobutyltitanate, tetra-tert-butyltitanate,tetra-n-pentyltitanate, tetra-n-hexyltitanate, tetraisooctyltitanate,and tetra-n-lauryltitanate, etc.

Of those, there are preferred tetraisoproyltitanate,tetra-n-butyltitanate, and tetra-tert-butyltitanate.

In the case of compounds in which m exceeds 1, there are preferred fromrespective dimers to respective dodecamers of tetraisobutyltitanate,tetra-tert-butyltitanate, tetraisoproyltitanate, andtetra-n-butyltitanate.

Zirconium chelate compounds can be prepared by mixing 1 mol of anzirconium compound represented by R--O-- Zr(OR)₂ --O!_(m) --Zr(OR)₂ --ORwherein R is an alkyl group or alkenyl group having a carbon number of 1to 20 which may be identical or different from each other, and m is aninteger of 0 to 20! with approximately 4 mol or less of the compoundcapable of forming the above-described keto or enol tautomer, optionallyfollowed by heating.

As the zirconates represented by R--O-- Zr(OR)₂ --O!_(m) --Zr(OR)₂ --OR,there are exemplified tetraethylzirconate, tetra-n-propylzirconate,tetraisopropylzirconate, tetraisobutylzirconate, tetra-n-butylzirconate,tetra-secbutylzirconate, tetra-tert-butylzirconate,tetra-n-pentylzirconate, tetra-tert-pentylzirconate,tetra-terthexylzirconate, tetra-n-heptylzirconate,tetra-n-octylzirconate, and tetra-n-stearylzirconate.

Of those, there are preferred tetraisopropylzirconate,tetra-n-propylzirconate, tetraisobutylzirconate, tetra-n-butylzirconate,tetra-sec-butylzirconate, and tetra-tert-butylzirconate.

In the case of compounds in which m exceeds 1, there are preferred fromrespective dimers to respective dodecamers of tetraisopropylzirconate,tetra-n-propylzirconate, tetra-n-butylzirconate, tetraisobutylzirconate,tetra-sec-butylzirconate, and tetra-tert-butylzirconate. Furthermore,there may be contained associate compounds of the zirconates.

Of the chelate compounds described hereinabove in the present invention,there are particularly preferred diisopropylate ethylacetoacetatealuminum, tris(ethylacetoacetate)aluminum,tris(n-propylacetoacetat)aluminum, tris(isopropylacetoacetate)aluminum,tris(n-butylacetoacetate)aluminum, isopropoxybisethyl acetoacetatealuminum, diisopropoxybisethyl acetoacetate aluminum,tris(acetylacetonate)aluminum, tris(ethylacetonate) aluminum,diisopropylate ethylacetonate aluminum, monoacetylacetonate aluminum,bis(ethylacetonate) aluminum, monoethylacetoacetatebis(acetylacetonat)aluminum, tris(isopropylate)aluminum,tris(sec-butylate)aluminum, diisopropylate mono-secbutoxyaluminum, andtris(acetylacetone) aluminum.

Furthermore, there are preferred titanium chelate compounds such asdiisopropoxy bis(ethylacetoacetate) titanium, diisopropoxybis(acetylacetate)titanium, and diisopropoxy bis(acetylacetone)titanium.

Still further, there are preferred zirconium chelate compounds such astetrakis(acetylacetone)zirconium,tetrakis(n-propylacetoacetate)zirconium,tetrakis(acetylacetonate)zirconium, andtetrakis(ethylacetonate)zirconium. There may be employed one or more ofthe above-described aluminum compounds titanium compounds, and zirconiumcompounds.

The chelate compounds are employed in the amount ranging from 0.01 to 30parts by weight, preferably from 0.05 to 15 parts by weight, and morepreferably from 0.5 to 10 parts by weight based on the total weight ofthe (meth)acrylic resins.

In the case when the amount is below 0.01 part by weight, curing bycrosslinking is insufficient and, on the contrary, in the case when itexceeds 30 parts by weight, the catalysts remained in cured articlesdecrease properties such as, for example, water absorption property andweatherability, etc. of the cured articles.

In the case when the thermosetting resin composition of the presentinvention is employed as a coating composition, there may be mixedmelamine-formaldehyde resins and/or isocyanate compounds and blockedisocyanates in order to increase crosslinking density.

It is to be noted that there may be preferably employed at least two ofthe functional groups capable of reacting with epoxy group in the(meth)acrylic resin having epoxy group-containing side chainsrepresented by general formula (1-3).

The (meth)acrylic resin having epoxy group-containing side chainsrepresented by general formula (1-3) in the thermosetting resincomposition of the present invention has a number average molecularweight of from 1,000 to 100,000, preferably from 2,000 to 50,000 on anaverage.

In the case when the molecular weight is below 1,000, mechanicalproperties in cured articles are not sufficient, and in the case when itexceeds 100,000, a viscosity considerably increases, resulting inlowering workability.

In the thermosetting resin composition of the present invention, theremay be mixed other epoxy compounds having a molecular weight below3,000.

The other epoxy compounds having a low molecular weight are effectivefor decreasing a viscosity of the thermosetting resin composition of thepresent invention, which effectively act as a reactive diluent.

The other epoxy compounds can be mixed in the amount of from 1 to 80% byweight, preferably from 5 to 60% by weight based on the total weight ofresin components in the thermosetting resin composition.

In the case when it is below 1%, the effect for decreasing viscosity isinsufficient, and in the case when it exceeds 80%, properties in curedarticles are deteriorated.

Still further, in the thermosetting resin composition of the presentinvention, there may be also mixed other components having oxiranering(s) and a molecular weight below 1,500 which are a diluent havingreactivity.

Use of the reactive diluent enables to decrease a use amount of solventsfor diluting which are discharged at working circumstances duringcuring.

As the diluent having reactivity which has a low molecular weight, thereare employed a bifunctional alicyclic compound (e.g.3,4-epoxycyclohexyl-3,4-cyclohexanecarboxylate such as Celloxide 2021and 2080-family manufactured by Daicel Chemical Industries, Ltd. and ERL4221 manufactured by Union Carbide Co., etc.), a multifunctionalalicyclic compound (e.g. Epolead GT-family manufactured by DaicelChemical Industries, Ltd.), an alkoxysilane compound of1,9-nonanediepoxide and 1,9-nonanemonoepoxide, a glycidylgroup-containing epoxy monomer such as diglycidylether of bisphenol A,diglycidylether of hydrogenated bisphenol A, diglycidylether ofcyclohexanedimethanol.

According to an eleventh aspect of the present invention, there isprovided a powder coating composition which comprises (A) a(meth)acrylic resin having epoxy group-containing side chainsrepresented by general formula (1-4)

    --COOCR.sup.a' R.sup.b' R.sup.c'                           (1-4)

wherein R^(a'), R^(b'), and R^(c') are each independently hydrogen orsubstituted group represented by general formula (2-2) ##STR10## atleast one of R^(a'), R^(b'), and R^(c') is not hydrogen, R², R⁶, R⁷, andR¹⁰ are each independently hydrogen or alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R⁸ and R⁹, areeach independently hydrogen or alkyl group having a carbon number of 1to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5 and (B) a curing agenthaving carboxylic groups.

A powder coating composition of the present invention includes the(meth)acrylic resin having epoxy group-containing side chainsrepresented by general formula (1-4) of the seventh aspect describedhereinabove and a curing agent having carboxylic groups.

The (meth)acrylic resin having epoxy group-containing side chainsrepresented by the general formula (1-4) has preferably an epoxyequivalent of from 100 to 2,000 and an average molecular weight of from300 to 2,000, preferably from 500 to 10,000. Also, the curing agenthaving carboxylic groups is preferably a multifunctional carboxylic acidhaving a molecular weight of below 500 or a carboxylic group-containingpolyester resin having an acid value of 15 to 200 mgKOH/g and asoftening point of 70° to 160° C.

In the case when the molecular weight is below 300, mechanical strengthin the coating layer becomes insufficient and, contrarily, in the casewhen it exceeds 20,000, fluidity of the coating in kneading and bakingbecomes inferior, resulting in deteriorating a clarity and smoothness ofthe coating layer.

Furthermore, in the case when a carboxylic group-containing polyesterresin is employed as a curing agent, a compatibility of the(meth)acrylic resin having epoxy group-containing side chains with thepolyester becomes inferior, resulting in insufficient crosslinkingreaction and insufficient properties of the coating layer.

In the component (A) a (meth)acrylic resin having epoxy group-containingside chains represented by the general formula (1-4), theepoxy(meth)acrylate represented by general formula (1-2) is employed ina ratio of from 5 to 100% by weight, preferably from 10 to 90% byweight, and more preferably from 10 to 70% by weight.

In the case when the ratio is below 5% by weight, kneading time cannotbe extended in the for powder coating composition compared toconventional powder coating compositions using a compound havingglycidyl group, and flow properties in coating before baking areinsufficient.

Furthermore, in the case when a carboxylic group-containing polyesterresin is employed as a curing agent, a compatibility of the(meth)acrylic resin having epoxy group-containing side chains with thepolyester becomes inferior, resulting in insufficient properties of thecoating layer.

As the preferred copolymerizable monomers to be copolymerized with theepoxy(meth)acrylate represented by the general formula (1-2), there areexemplified styrene, (meth)acrylates, fumaric diester, acrylonitrile,and acrylamide, etc. Of those, methylmethacrylate which is one of(meth)acrylates is particularly preferred from a viewpoint of Tg andweatherability.

As the curing agent having carboxylic groups which is the component (B)of the present invention, there can be preferably employed a compoundhaving a chemical formula R--(COOH)_(n) wherein R is an alkylene grouphaving a straight chain or branched chain having a carbon number of 1 to25, an alicyclic alkyl group, an aromatic group, and a cyclic ringhaving a plurality of elements, and n is a integer of 2 to 5!.

Specifically, there are exemplified succinic acid, adipic acid, pimelicacid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid,malonic ester, phthalic acid, trimellitic acid, pyromellitic acid,benzophenone tetracarboxylic acid, ethyleneglycol bis(trimellitate),glyceroltris(trimellitate), tetrahydrocarboxylic acid,methyl-tetrahydrocarboxylic acid, nadic acid, alkenyl succinic acid,hexahydrophthalic acid, methylhexahydrophthalic acid, methylcyclohexenetetracarboxylic acid, a dimer acid, and triscarboxyethyl isocyanurate,etc.

Furthermore, as the curing agent having carboxylic groups which is thecomponent (B) of the present invention, there can be also preferablyemployed a polyester resin having carboxylic groups at terminals.

Although conventional (meth)acrylic resins having epoxy groups usingglycidyl methacrylate are poor in a compatibility with the polyesterresin having carboxylic groups at terminals, the (meth)acrylic resinhaving epoxy group-containing side chains represented by the generalformula (1-4) which is the component (A) in a powder coating compositionof the present invention is very excellent in compatibility with thepolyester resin, resulting in being capable of providing coating layershaving excellent properties.

The polyester resin having carboxylic groups at terminals has preferablyan acid value ranging from 15 to 200 mgKOH/g, a softening point rangingfrom 70° to 160° C., more preferably from 100° to 130° C., and numberaverage molecular weight ranging from 500 to 20,000, more preferablyfrom 1,000 to 15,000.

Although the polyester resin may have a branched, linear, and mixedstructure thereof, linear structure not having branched structure somuch is more preferred from viewpoint of fluidity in melting, outerappearances of coating layers after baking, and gloss of the coatinglayers.

The polyester resin having carboxylic groups at terminals can belimitlessly prepared by the esterification between polybasic acids oranhydrides thereof and polyols using conventional catalysts.

As the polybasic acids or anhydrides to be employed for the preparationof the polyester resin, there are exemplified terephthalic acid,isophthalic acid, methylterephthalic acid, trimellitic acid,pyromellitic acid, and anhydrides or alkyl esters thereof, adipic acid,sebacic acid, succinic acid, maleic acid, fumaric acid,tetrahydrophthalic acid, methyl-tetrahydrophthalic acid,hexahydrophthalic acid, methylhexahydrophthalic acid, and anhydrides oralkyl esters thereof.

As the polyols to be employed for the preparation of the polyesterresin, there are exemplified ethyleneglycol, propyleneglycol,1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentylglycol,bishydroxyethyl terephthalate, hydrogenated bisphenol A, ethyleneglycoladducts of hydrogenated bisphenol A, propyleneglycol adducts ofhydrogenated bisphenol A, trimethylolpropane, trimethylolethane,glycerine, pentaerythritol, 2,2,4-trimethylpentane-1,3-diol,monoepoxides such as alpha-olefinmonoepoxide, etc.

Furthermore, there can be employed lactone polyols derived from cycliclactones and the above-described polyols. As the cyclic lactones, thereare employed epsilon-caprolactone, 4-methylcaprolactone,2-methylcaprolactone, delta-valerolactone,beta-methyl-delta-valerolactone, beta-propiolactone, andgamma-butyrolactone, etc. There may be employed one or more of lactones.

(n+1) mol of the polybasic acids are allowed to react with n mol of thepolyols to prepare the polyester resin having carboxylic groups atterminals.

The esterification between the polybasic acids or anhydrides thereof andthe polyols is carried out in a temperature ranging from 130° to 240°C., preferably from 140° to 230° C. while streaming an inert gas such asnitrogen gas, etc., whereby there can be preferably preventeddeterioration and coloring of a resulting polyester resin by oxidation.

The esterification is carried out in the presence of catalysts.

Specific examples of the catalysts, there are exemplified tin compoundssuch as stannous octylate, dibutyltin dilaurate, monobutyltin oxide,dibutyltin oxide, monobutyltin hydroxybutyloxide, and stannous chloride,etc., titanium compounds such as tetrabutyl titanate, tetraethyltitanate, and tetraisopropyl titanate, etc.

The catalysts are employed in an amount ranging from 0.1 ppm to 1000ppm, preferably from 1 ppm to 100 ppm based on the total amount ofstarting materials. In the case when it exceeds 1000 ppm, a productunpreferably colors and a stability in a product is adversely affected.On the contrary, in the case when it is below 0.1 ppm, theesterification velocity becomes unpreferably slow.

Thus-obtained polyester resin having carboxylic groups at terminals ismixed with the (meth)acrylic resin having epoxy group-containing sidechains represented by the general formula (1-4) to prepare the powdercoating composition of the present invention.

In the powder coating composition of the present invention, theequivalent ratio of epoxy groups to carboxylic groups is 0.5 to 2.0,preferably 0.7 to 1.4.

In the case when the equivalent ratio is below 0.5 or exceeds 2.0,curing velocity becomes exceedingly slow, and there can not be obtainedcured coating layers having sufficient properties.

In order to prepare the powder coating composition of the presentinvention, the component (A) which is a (meth)acrylic resin having epoxygroup-containing side chains and the component (B) which is a curingagent are mixed with pigments, silicone compounds, fluidity controllingagents such as a polymer of 2-ethylhexylacrylate, amine-based orphosphoric acid-based catalysts for curing such as tertiary aminecompounds, quaternary amine compounds, triphenyl phosphine, andphosphonium salts, etc., and further other additives, followed bykneading by an extruder, etc., crushing and classifying.

The powder coating composition of the present invention can be coatedwith electrostatic coating methods or flowing bed coating methods whichare conventional methods.

In the following, although the present invention is specificallyillustrated below by Examples, it is not limited.

EXAMPLE 1 <Preparation of a methacrylate having alkenyl grouprepresented by the general formula (1-1)>

A teardrop type flask equipped with a stirrer, a tube for blowing air, atube for removing water, and a reflux condenser was charged with 600parts by weight of oleic alcohol having a hydroxyl value of 213 (thetrade name, UNJECOL-90N manufactured by Shin-Nihon Rika, Ltd.), 392parts by weight of methacrylic acid, 400 parts by weight of n-heptane,1.0 part by weight of p-toluene sulfonic acid, and 4.96 parts by weightof hydroquinone monomethylether, followed by carrying out esterificationreaction accompanied by dehydration at 120° C.

The reaction was carried out for approximately 9 hours. After thecompletion of the reaction, a reaction crude solution was washed with anaqueous alkali solution and then washed with water twice in order toremove unreacted methacrylic acid and p-toluene sulfonic acid.Subsequently, low boiling point ingredients were removed with anevaporator while blowing air to obtain 749 parts by weight of amethacrylate.

Delta values of ¹ H-NMR related to the methacrylate are shown below.

Delta (ppm)

Vicinity of 0.8-1.0 (3.0H): proton in terminated --CH₃

Vicinity of 1.2-1.7 (26H): proton in long chain --CH₂ --

Vicinity of 1.95-2.1 (6.2H): proton in --CH₃ of methacrylic group andproton in --CH₂ --adjacent to double bond carbon

Vicinity of 4.1-4.2 (2.0H): proton in --CH₂ --group bonded to oxygenatom of ester bond

Vicinity of 5.3-5.5 (1.7H): proton in CH₂ ═

Vicinity of 5.5-5.6 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 6.1-6.2 (1.0H): one proton in CH₂ ═ in methacrylic group

It was identified that the methacrylate has the following chemicalformula. ##STR11##

EXAMPLE 2 <Preparation of a methacrylate having alkenyl grouprepresented by the general formula (1-1)>

A teardrop type flask equipped with a stirrer, a tube for blowing air, atube for removing water, and a reflux condenser was charged with 400parts by weight of 3-methyl-3-butene-1-ol (a trade name, Isoprenolmanufactured by Kuraray, Ltd.), 800 parts by weight of methacrylic acid,400 parts by weight of n-heptane, 1.2 parts by weight of monobutyltinoxide, and 6.0 parts by weight of hydroquinone monomethylether, followedby carrying out esterification reaction accompanied by dehydration at120° C.

The reaction was carried out for approximately 12 hours. After thecompletion of the reaction, a reaction crude solution was washed with anaqueous alkali solution and then washed with water twice in order toremove unreacted methacrylic acid, etc. Subsequently, low-boiling-pointingredients were removed with an evaporator while blowing air to obtain507.1 parts by weight of a methacrylate. Delta values of ¹ H-NMR relatedto the methacrylate are shown below.

Delta (ppm)

Vicinity of 1.7-1.8 (3.0H): proton in --CH₃ bonded to double bond carbon

Vicinity of 1.95 (3.0H): proton in --CH₃ of methacrylic group

Vicinity of 2.3-2.5 (2.0H): proton in --CH₂ -- adjacent to double bondcarbon

Vicinity of 4.2-4.3 (2.0H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

Vicinity of 4.7-4.9 (1.0H): proton in CH₂ ═

Vicinity of 5.5-5.6 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 6.1-6.2 (1.0H): one proton in CH₂ ═ in methacrylic group

By the values, it is identified that 3-methyl-3-butenyl of methacrylicacid was obtained which is a desired product having the followingchemical formula. ##STR12##

EXAMPLE 3 <Preparation of a methacrylate having alkenyl grouprepresented by the general formula (1-1)>

A teardrop type flask equipped with a stirrer, a tube for blowing air, atube for removing water, and a reflux condenser was charged with 400parts by weight of 3-methyl-2-butene-1-ol (a trade name, Prenolmanufactured by Kuraray, Ltd.), 800 parts by weight of methacrylic acid,400 parts by weight of n-heptane, 1.2 parts by weight of titaniumtetrabutoxide, and 6.0 parts by weight of hydroquinone monomethylether,followed by carrying out esterification reaction accompanied bydehydration at 120° C. The reaction was carried out for approximately 12hours. After the completion of the reaction, a reaction crude solutionwas washed with an aqueous alkali solution and then washed with watertwice in order to remove unreacted methacrylic acid, etc. Subsequently,low-boiling-point ingredients were removed with an evaporator whileblowing air to obtain 555.9 parts by weight of a product. Delta valuesof ¹ H-NMR related to the product are shown below.

Delta (ppm)

Vicinity of 1.7-1.8 (6.0H): proton in --CH₃ bonded to double bond carbon

Vicinity of 1.95 (3.0H): proton in --CH₃ of methacrylic group

Vicinity of 4.6-4.7 (2.0H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

Vicinity of 5.3-5.5 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 5.5-5.6 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 6.1-6.2 (1.0H): one proton in CH₂ ═ in methacrylic group

By the values, it is identified that 3-methyl-2-butenyl of methacrylicacid was obtained which is a desired product having the followingchemical formula. ##STR13##

EXAMPLE 4 <Preparation of a methacrylate having alkenyl grouprepresented by the general formula (1-1)>

A teardrop type flask equipped with a stirrer, a tube for blowing air, atube for removing water, and a reflux condenser was charged with 250parts by weight of 7-octene-1-ol (a trade name, 7-OEA manufactured byKuraray, Ltd.), 205 parts by weight of methacrylic acid, 200 parts byweight of n-heptane, 0.46 g of p-toluene sulfonic acid, and 1.35 g ofhydroquinone monomethylether, followed by carrying out esterificationreaction accompanied by dehydration at 120°C. The reaction was carriedout for approximately 9 hours. After the completion of the reaction, areaction crude solution was washed with an aqueous alkali solution andthen washed with water twice in order to remove unreacted methacrylicacid, etc.

Subsequently, low-boiling-point ingredients were removed with anevaporator while blowing air to obtain 361.0 parts by weight of aproduct. Delta values of ¹ H-NMR related to the product are shown below.

Delta (ppm)

Vicinity of 1.2-1.85 (10H): proton in --CH₂ -- group

Vicinity of 2.0-2.1 (2.0H): proton in --CH₂ -- adjacent to vinyl group

Vicinity of 1.95 (3.0H): proton in --CH₃ of methacrylic group

Vicinity of 4.1-4.2 (2.1H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

Vicinity of 4.9-5.1 (1.6H): proton in CH₂ ═ of vinyl group

Vicinity of 5.5-5.6 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 5.7-5.9 (0.8H): proton in --CH═ of vinyl group

Vicinity of 6.1-6.2 (1.0H): one proton in CH₂ ═ in methacrylic group

By the values, it is identified that 7-octenyl of methacrylic acid wasobtained which is a desired product having the following chemicalformula. ##STR14##

EXAMPLE 5 <Preparation of a methacrylate having alkenyl grouprepresented by the general formula (1-1)>

A teardrop type flask equipped with a stirrer, a tube for blowing air, atube for removing water, and a reflux condenser was charged with 378parts by weight of 2,7-octadienol (a trade name, ODA manufactured byKuraray, Ltd.), 310 parts by weight of methacrylic acid, 200 parts byweight of n-heptane, 2.1 g of p-toluene sulfonic acid, and 3.4 g ofhydroquinone monomethylether, followed by carrying out esterificationreaction accompanied by dehydration at 120° C. The reaction was carriedout for approximately 9 hours. After the completion of the reaction, areaction crude solution was washed with an aqueous alkali solution andthen washed with water twice in order to remove unreacted methacrylicacid, etc.

Subsequently, low-boiling-point ingredients were removed with anevaporator while blowing air to obtain 489.8 parts by weight of aproduct.

Delta values of ¹ H-NMR related to the product are shown below.

It was identified that the product has the following chemical formula.##STR15##

EXAMPLE 6 <Preparation of an acrylate having alkenyl group representedby the general formula (1-1)>

A teardrop type flask equipped with a stirrer, a tube for blowing air, atube for removing water, and a reflux condenser was charged with 250parts by weight of 7-octene-1-ol (a trade name, 7-OEA manufactured byKuraray, Ltd.), 169 parts by weight of acrylic acid, 200 parts by weightof n-heptane, 0.42 g of p-toluene sulfonic acid, and 1.26 g ofhydroquinone monomethylether, followed by carrying out esterificationreaction accompanied by dehydration at 1200°C. The reaction was carriedout for approximately 9 hours. After the completion of the reaction, areaction crude solution was washed with an aqueous alkali solution andthen washed with water twice in order to remove unreacted acrylic acid,etc.

Subsequently, low-boiling-point ingredients were removed with anevaporator while blowing air to obtain 318.2 parts by weight of aproduct.

Delta values of ¹ H-NMR related to the product are shown below.

Delta (ppm)

Vicinity of 1.2-1.85 (10H): proton in --CH₂ -- group

Vicinity of 2.0-2.1 (2.0H): proton in --CH₂ -- adjacent to vinyl group

Vicinity of 4.1-4.2 (2.1H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

Vicinity of 4.9-5.1 (1.6H): proton in CH₂ ═ of vinyl group

Vicinity of 6.0-6.2 (1.0H): proton in --CH═ of acrylic group

Vicinity of 6.3-6.5 (1.0H): one proton in CH₂ ═ in acrylic group

By the values, it is identified that 7-octenyl of acrylic acid wasobtained which is a desired product having the following chemicalformula.

    CH.sub.2 ═CH--COO--(CH.sub.2).sub.6 --CH═CH.sub.2

EXAMPLE 7 <Preparation of a methacrylate having alkenyl grouprepresented by the general formula (1-1)>

A 2L-teardrop type flask equipped with a stirrer, a tube for blowingair, a tube for removing water, and a reflux condenser was charged with400 parts by weight of 1,7-octadiene-3-ol, 328 parts by weight ofmethacrylic acid, 200 parts by weight of n-heptane, 0.73 part ofp-toluene sulfonic acid, and 2.18 part of hydroquinone monomethylether,followed by carrying out esterification reaction accompanied bydehydration at 120° C. The reaction was carried out for approximately 8hours. After the completion of the reaction, a reaction crude solutionwas washed with an aqueous alkali solution and then washed with watertwice in order to remove unreacted methacrylic acid, etc.

Subsequently, low-boiling-point ingredients were removed with anevaporator while blowing air to obtain 575 parts by weight of a product.It is identified that the product has the following chemical formula.##STR16##

EXAMPLE 8 <Preparation of an acrylate having alkenyl group representedby the general formula (1-1)>

A 2L-teardrop type flask equipped with a stirrer, a tube for blowingair, a tube for removing water, and a reflux condenser was charged with400 parts by weight of 2,7-octadienol (a trade name of ODA manufacturedby Kuraray, Ltd.), 274 parts by weight of acrylic acid, 200 parts byweight of n-heptane, 0.67 part of p-toluene sulfonic acid, and 2.02 partof hydroquinone monomethylether, followed by carrying out esterificationreaction accompanied by dehydration at 120° C. The reaction was carriedout for approximately 8 hours. After the completion of the reaction, areaction crude solution was washed with an aqueous alkali solution andthen washed with water twice in order to remove unreacted acrylic acid,etc.

Subsequently, low-boiling-point ingredients were removed with anevaporator while blowing air to obtain 526 parts by weight of a product.

It is identified that the product has the following chemical formula.##STR17##

EXAMPLE 9 <Preparation of an epoxymethacrylate represented by thegeneral formula (1-2)>

A jacketed-reaction vessel equipped with a reflux con-denser,thermometer, and an agitator having blades was charged with 500 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR18## and 0.5 parts by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 370.3 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.16 part by weight ofpotassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4.5 hours, and further agingwas carried out for 2 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain488.8 parts by weight of an epoxymethacrylate. Delta values of ¹ H-NMRrelated to the epoxymethacrylate are shown below.

Delta (ppm)

Vicinity of 0.8-1.0 (3.0H): proton in terminated --CH₃

Vicinity of 1.2-1.8 (30.0H): proton in CH₂ chain

Vicinity of 1.95 (3.0H): proton in --CH₃ of methacrylic group

Vicinity of 2.6-2.7 and Vicinity of 2.8-3.0 (1.8H): proton in epoxygroup

Vicinity of 4.1-4.2 (2.1H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

It was identified that the epoxymethacrylate has the following chemicalformula which is a desired product. ##STR19##

EXAMPLE 10 <Preparation of an epoxymethacrylate represented by thegeneral formula (1-2)>

A jacketed-reaction vessel equipped with a reflux con-denser,thermometer, and an agitator having blades was charged with 400 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR20## and 0.4 part by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 800.3 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.40 part by weight ofpotassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4.5 hours, and further agingwas carried out for 4 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain308.6 parts by weight of an epoxymethacrylate. Delta values of ¹ H-NMRrelated to the epoxymethacrylate are shown below.

Delta (ppm)

Vicinity of 1.4 (3.0H): proton in --CH₃ bonded to epoxy group

Vicinity of 1.8-2.0 (3.0H): proton in --CH₃ of methacrylic group andproton in --CH₂ adjacent to epoxy group

Vicinity of 2.6-2.7 (2.0H): proton in --CH₂ -- of epoxy group

Vicinity of 4.2-4.4 (2.0H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

Vicinity of 5.6 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 6.1 (1.0H): one proton in CH₂ ═ in methacrylic group

By the values, it is identified that 3-methyl-3,4-epoxybutylmethacrylate was obtained which is a desired product having thefollowing chemical formula. ##STR21##

EXAMPLE 11 <Preparation of an epoxymethacrylate represented by thegeneral formula (1-2)>

A jacketed-reaction vessel equipped with a reflux condenser,thermometer, and an agitator having blades was charged with 400 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR22## and 0.4 part by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 800.3 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.40 g of potassiumpyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4 hours, and further agingwas carried out for 4 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain351.6 parts by weight of an epoxymethacrylate. Delta values of ¹ H-NMRrelated to the epoxymethacrylate are shown below.

Delta (ppm)

Vicinity of 1.3-1.4 (6.0H): proton in --CH₃ bonded to epoxy group

Vicinity of 1.95 (3.0H): proton in --CH₃ of methacrylic group

Vicinity of 3.0-3.1 (1.0H): proton in --CH of epoxy group

Vicinity of 4.1 (1.0H): proton in --CH₂ -- group bonded to oxygen atomof ester bond

Vicinity of 4.4 (1.0H): proton in --CH₂ -- group bonded to oxygen atomof ester bond

Vicinity of 5.6 (1.0H): one proton in CH₂ ═ in methacrylic group

Vicinity of 6.1 (1.0H): one proton in CH₂ ═ in methacrylic group

By the values, it is identified that 3-methyl-2,3-epoxybutylmethacrylate was obtained which is a desired product having thefollowing chemical formula. ##STR23##

EXAMPLE 12 <Preparation of an epoxymethacrylate represented by thegeneral formula (1-2)>

A jacketed-reaction vessel equipped with a reflux con-denser,thermometer, and an agitator having blades was charged with 315 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR24## and 0.32 part by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 495.2 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.33 part by weight ofpotassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4 hours, and further agingwas carried out for 6 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain311.0 parts by weight of an epoxymethacrylate. Delta values of ¹ H-NMRrelated to the epoxymethacrylate are shown below.

Delta (ppm)

Vicinity of 1.2-1.8 (10H): proton in --CH₂ -- group

Vicinity of 1.95 (3.0H): proton in --CH₃ of methacrylic group

Vicinity of 2.4-2.5 (1.0H): one proton in --CH₂ of epoxy group

Vicinity of 2.7-2.8 (1.0H): one proton in --CH₂ -- of epoxy group

Vicinity of 2.9 (1.0H): proton in --CH-- of epoxy group

Vicinity of 4.1-4.2 (2.1H): proton in --CH₂ -- group bonded to oxygenatom of ester bond

Vicinity of 5.5-5.6 (1.0H): one proton in CH2═ in methacrylic group

Vicinity of 6.1 (1.0H): one proton in CH₂ ═ in methacrylic group

By the values, it is identified that 7,8-epoxy octyl-methacrylate wasobtained which is a desired product having the following chemicalformula. ##STR25##

EXAMPLE 13 <Preparation of an epoxymethacrylate represented by thegeneral formula (1-2)>

A jacketed-reaction vessel equipped with a reflux condenser,thermometer, and an agitator having blades was charged with 400 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR26## and 0.4 part by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 1270.5 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.64 part by weight ofpotassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4 hours, and further agingwas carried out for 6 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain420.3 parts by weight of an epoxymethacrylate.

It was identified that the epoxymethacrylate has the following chemicalformula. ##STR27##

EXAMPLE 14 <Preparation of an epoxyacrylate represented by the generalformula (1-2)>

A jacketed-reaction vessel equipped with a reflux condenser,thermometer, and an agitator having blades was charged with 250 parts byweight of the acrylate having an alkenyl group represented by thefollowing chemical formula

    CH.sub.2 ═CH--COO--(CH.sub.2).sub.6 --CH═CH.sub.2

and 0.25 part by weight of hydroquinone monomethylether, followed bycarrying out epoxidation reaction by adding dropwise 423.2 parts byweight of an ethyl acetate solution containing 29.6% of peracetic acidand 0.21 part by weight of potassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4 hours, and further agingwas carried out for 6 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain245.0 parts by weight of an epoxyacrylate.

It was identified that the epoxyacrylate has the following chemicalformula. ##STR28##

EXAMPLE 15 <Preparation of an epoxyacrylate represented by the generalformula (1-2)>

A jacketed-reaction vessel equipped with a reflux condenser,thermometer, and an agitator having blades was charged with 400 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR29## and 0.4 part by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 1270.5 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.64 part by weight ofpotassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4.5 hours, and further agingwas carried out for 4 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain389 parts by weight of an epoxyacrylate.

It was identified that the epoxyacrylate has the following chemicalformula. ##STR30##

EXAMPLE 16 <Preparation of an epoxyacrylate represented by the generalformula (1-2)>

A jacketed-reaction vessel equipped with a reflux condenser,thermometer, and an agitator having blades was charged with 400 parts byweight of the acrylate having an alkenyl group represented by thefollowing chemical formula ##STR31## and 0.4 part by weight ofhydroquinone monomethylether, followed by carrying out epoxidationreaction by adding dropwise 1369.4 parts by weight of an ethyl acetatesolution containing 29.6% of peracetic acid and 0.68 part by weight ofpotassium pyrophosphate while blowing air.

The reaction was carried out at 40° C. for 4.5 hours, and further agingwas carried out for 3 hours. After the completion of the reaction, areaction crude solution was washed with water thrice. Subsequently,low-boiling-point ingredients were removed with an evaporator to obtain428 parts by weight of an epoxyacrylate.

It was identified that the epoxyacrylate has the following chemicalformula. ##STR32##

EXAMPLE 17 <Measurements of a reactivity relating to theepoxy(meth)acrylates obtained in Examples 9-12 and 14, and conventionalepoxymethacrylates>

A flask was charged with 0.025 mol of the respectiveepoxy(meth)acrylates obtained in Examples 9-12 and 14, and3,4-epoxycyclohexylmethylmethacrylate, beta-methylglycidyl methacrylate,and glycidyl methacrylate which are conventional epoxy methacrylates,and 50 g of dichloroethane while stirring, followed by controlling thetemperature at 20° C. after adding 0.8 g of methanol. Subsequently, adichloroethane solution containing 24 mg of BF₃ (OC₂ H₅)₂ was added tomeasure the reactivity of epoxy group.

Measurements were carried out by monitoring oxirane oxygen.

Results are shown in FIG. 1. The curves (a), (b), (c), (d), and (e)exhibit the respective reactivity of the epoxymethacrylates obtained inthe Examples 9-12 and 14, respectively.

The curves (f), (g), and (h) exhibit the respective reactivity of3,4-epoxycyclohexylmethylmethacrylate, beta-methylglycidyl methacrylate,and glycidyl methacrylate which are conventional epoxy methacrylates.

EXAMPLE 18 <Preparation of a methacrylic resin having alkenylgroup-containing side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding43 parts by weight of the methacrylate having an alkenyl grouprepresented by the following chemical formula ##STR33##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andperbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylate resin.

The reaction liquid was analyzed by an internal standard method of gaschromatography to identify less than 1% of the residual methacrylatehaving an alkenyl group. It was identified that the reaction liquidcontains 30% of the methacrylate resin having a number average molecularweight of 18,000.

EXAMPLE 19 <Preparation of a methacrylic resin having alkenylgroupcontaining side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding54 parts by weight of methylmethacrylate, 6 parts by weight ofmethacrylic acid, and 40 parts by weight of the methacrylate having analkenyl group represented by the following chemical formula ##STR34##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andperbutyl 0 was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin.

The reaction liquid was analyzed by an internal standard method of gaschromatography to identify less than 1% of the residual methacrylatehaving an alkenyl group. It was identified that the reaction liquidcontains 50% of the methacrylate resin having a number average molecularweight of 20,000 and an acid value of 18.5 mgKOH/g.

EXAMPLE 20 <Preparation of a methacrylic resin having alkenylgroup-containing side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding54 parts by weight of methylmethacrylate, 6 parts by weight ofmethacrylic acid, and 40 parts by weight of the methacrylate having analkenyl group represented by the following chemical formula ##STR35##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin.

The reaction liquid was analyzed by an internal standard method of gaschromatography to identify less than 1% of the residual methacrylatehaving an alkenyl group. It was identified that the reaction liquidcontains 50% of the methacrylate resin having a number average molecularweight of 17,000 and an acid value of 18.7 mgKOH/g.

EXAMPLE 21 <Preparation of a methacrylic resin having alkenylgroup-containing side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding54 parts by weight of methylmethacrylate, 6 parts by weight ofmethacrylic acid, and 40 parts by weight of the methacrylate having analkenyl group represented by the following chemical formula ##STR36##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin.

The reaction liquid was analyzed by an internal standard method of gaschromatography to identify less than 1% of the residual methacrylatehaving an alkenyl group. It was identified that the reaction liquidcontains 50% of the methacrylate resin having a number average molecularweight of 17,000 and an acid value of 18.7 mgKOH/g.

EXAMPLE 22 <Preparation of a methacrylic resin having alkenylgroup-containing side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding54 parts by weight of methylmethacrylate, 6 parts by weight ofmethacrylic acid, and 40 parts by weight of the methacrylate having analkenyl group represented by the following chemical formula ##STR37##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin.

The reaction liquid was analyzed by an internal standard method of gaschromatgraphy to identify less than 1% of the residual methacrylatehaving an alkenyl group. It was identified that the reaction liquidcontains 50% of the methacrylate resin having a number average molecularweight of 17,000 and an acid value of 19.1 mgKOH/g.

EXAMPLE 23 <Preparation of a methacrylic resin having alkenylgroup-containing side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding54 parts by weight of methylmethacrylate, 5 parts by weight of n-butylacrylate, 5 parts by weight of 2-hydroxyethyl methacrylate, 3 parts byweight of methacrylic acid, 5 parts by weight of acaprolactone-modifiedhydroxyethyl methacrylate having average molecularweight of 244 (PCL-FM1 manufactured by Daicel Chemical Industries,Ltd.), and 10 parts by weight of the methacrylate having an alkenylgroup represented by the following chemical formula ##STR38##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin. The reaction liquid wasanalyzed by an internal standard method of gas chromatgraphy to identifyless than 1% of the residual methacrylate having an alkenyl group. Itwas identified that the reaction liquid contains 38% of the methacrylateresin having a number average molecular weight of 20,000 and an acidvalue of 12.3 mgKOH/g, and a hydroxyl value of 20.1 mgKOH/g.

EXAMPLE 24 <Preparation of a methacrylic resin having alkenylgroup-containing side chains represented by the general formula (1-3)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing air was charged with 50parts by weight of xylene and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding20 parts by weight of methylmethacrylate, 5 parts by weight of acrylicacid, 10 parts by weight of styrene, 5 parts by weight of 2-hydroxyethylmethacrylate, 2 parts by weight of methacrylic acid, 5 parts by weightof a caprolactone-modified hydroxyethyl methacrylate (PCL FM-1manufactured by Daicel Chemical Industries, Ltd.), and 10 parts byweight of the methacrylate having an alkenyl group represented by thefollowing chemical formula ##STR39##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin.

The reaction liquid was analyzed by an internal standard method of gaschromatgraphy to identify less than 1% of the residual methacrylatehaving an alkenyl group. It was identified that the reaction liquidcontains 37% of the methacrylate resin having a number average molecularweight of 17,000, an acid value of 8.0 mgKOH/g, and a hydroxyl value of20.5 mgKOH/g.

EXAMPLE 25 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A separable flask equipped with an agitator, thermometer, a refluxcondenser, a dropwise funnel, a tube for blowing nitrogen was chargedwith 50 parts by weight of dioxane and 3 parts by weight of Perbutyl O(manufactured by Nihon Yushi, Ltd.) as an initiator, followed by adding43 parts by weight of the epoxymethacrylate represented by the followingchemical formula

    CH.sub.2 ═CH--COO--(CH.sub.2).sub.6 --CH═CH.sub.2

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction liquid containing a methacrylic resin having epoxygroup-containing side chains.

The reaction liquid was analyzed by an internal standard method of gaschromatgraphy to identify less than 1% of the residualepoxymethacrylate. It was identified that the reaction liquid contains30% of the methacrylic resin having epoxy group-containing side chainshaving a number average molecular weight of 20,000.

EXAMPLE 26 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 54 parts by weight of methylmethacrylate,6 parts of methacrylic acid, 40 parts by weight of the epoxymethacrylaterepresented by the following chemical formula ##STR40##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 50% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 20,000, oxirane oxygen concentrationof 1.3%, and an acid value of 18.5 mgKOH/g.

EXAMPLE 27 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 54 parts by weight of methylmethacrylate,6 parts of methacrylic acid, 40 parts by weight of the epoxymethacrylaterepresented by the following chemical formula ##STR41##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was as a solution containing 48% of themethacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 19,000, oxirane oxygen concentrationof 1.6%, and an acid value of 17.5 mgKOH/g.

EXAMPLE 28 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 54 parts by weight of methylmethacrylate,6 parts of methacrylic acid, 40 parts by weight of the epoxymethacrylaterepresented by the following chemical formula ##STR42##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 48% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 19,000, oxirane oxygen concentrationof 1.6%, and an acid value of 17.5 mgKOH/g.

EXAMPLE 29 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general `formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 35 parts by weight of methylmethacrylate,5 parts of n-butyl acrylate, 5 parts by weight of the2-hydroxyethylmethacrylate, 3 parts by weight of methacrylic acid, 15parts by weight of the epoxymethacrylate represented by the followingchemical formula ##STR43##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition.

The reaction composition was obtained as a solution containing 39.5% ofa methacrylic resin having epoxy group-containing side chains which hasa number average molecular weight of 5,000, oxirane oxygen concentrationof 1.1%, an acid value of 11.0 mgKOH/g, and a hydroxyl value of 13mgKOH/g.

EXAMPLE 30 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 30 parts by weight of methylmethacrylate,5 parts of n-butyl acrylate, 5 parts by weight of the2-hydroxyethylmethacrylate, 3 parts by weight of methacrylic acid, 5parts by weight of a caprolactone-modified hydroxyethyl methacrylate(PCL FM-1 manufactured by Daicel Chemical Industries, Ltd.), and 10parts by weight of the epoxymethacrylate represented by the followingchemical formula ##STR44##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 40.2% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 5,500, oxirane oxygen concentrationof 1.2%, an acid value of 12.0 mgKOH/g, and a hydroxyl value of 12.5mgKOH/g.

EXAMPLE 31 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 30 parts by weight of methylmethacrylate,5 parts of n-butyl acrylate, 5 parts by weight of the2-hydroxyethylmethacrylate, 3 parts by weight of methacrylic acid, 5parts by weight of a caprolactone-modified hydroxyethyl methacrylate(PCL FM-1 manufactured by Daicel Chemical Industries, Ltd.), and 10parts by weight of the epoxymethacrylate represented by the followingchemical formula ##STR45##

The dropwise funnel was charged with 50 parts by weight of xylene and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 39% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 7,000, oxirane oxygen concentrationof 0.40%, an acid value of 12.0 mgKOH/g, and a hydroxyl value of 18.0mgKOH/g.

EXAMPLE 32 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 30 parts by weight of methylmethacrylate,5 parts of n-butyl acrylate, 5 parts by weight of the2-hydroxyethylmethacrylate, 3 parts by weight of methacrylic acid, 5parts by weight of a caprolactone-modified hydroxyethyl methacrylate(PCL FM-1 manufactured by Daicel Chemical Industries, Ltd.), and 10parts by weight of the epoxymethacrylate represented by the followingchemical formula ##STR46##

The dropwise funnel was charged with 50 parts by weight of xylene and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 40% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 4,900, oxirane oxygen concentrationof 0.89%, an acid value of 11.9 mgKOH/g, and a hydroxyl value of 19.0mgKOH/g.

EXAMPLE 33 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of xylene and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 20 parts by weight of methylmethacrylate,5 parts of n-butyl acrylate, 10 parts by weight of styrene, 5 parts byweight of the 2-hydroxyethylmethacrylate, 2 parts by weight ofmethacrylic acid, 5 parts by weight of a caprolactone-modifiedhydroxyethyl methacrylate (PCL FM-1 manufactured by Daicel ChemicalIndustries, Ltd.), and 10 parts by weight of the epoxymethacrylaterepresented by the following chemical formula ##STR47##

The dropwise funnel was charged with 50 parts by weight of xylene and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 3 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 38.1% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 5,800, oxirane oxygen concentrationof 0.52%, an acid value of 8.0 mgKOH/g, and a hydroxyl value of 19.0mgKOH/g.

EXAMPLE 34 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of xylene and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 20 parts by weight of methylmethacrylate,5 parts of n-butyl acrylate, 10 parts by weight of styrene, 5 parts byweight of the 2-hydroxyethylmethacrylate, 2 parts by weight ofmethacrylic acid, 5 parts by weight of a caprolactone-modifiedhydroxyethyl methacrylate (PCL FM-1 manufactured by Daicel ChemicalIndustries, Ltd.), and 10 parts by weight of the epoxymethacrylaterepresented by the following chemical formula ##STR48##

The dropwise funnel was charged with 50 parts by weight of xylene and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 3 hours, followed by aging over 3 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 37.9% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 6,200, oxirane oxygen concentrationof 0.48%, an acid value of 7.8 mgKOH/g, and a hydroxyl value of 20.2mgKOH/g.

EXAMPLE 35 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of xylene and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 54 parts by weight of methylmethacrylate,6 parts by weight of methacrylic acid, and 40 parts by weight of theepoxymethacrylate represented by the following chemical formula##STR49##

The dropwise funnel was charged with 50 parts by weight of xylene and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 4 hours to obtain areaction composition containing a methacrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 49% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 6,500, oxirane oxygen concentrationof 0.69%, an acid value of 18.7 mgKOH/g.

EXAMPLE 36 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 1-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 50 parts by weight of dioxane and 3 parts byweight of Perbutyl O (manufactured by Nihon Yushi, Ltd.) as aninitiator, followed by adding 54 parts by weight of methylmethacrylate,6 parts by weight of methacrylic acid, and 40 parts by weight of theepoxyacrylate represented by the following chemical formula ##STR50##

The dropwise funnel was charged with 50 parts by weight of dioxane and 4parts by weight of Perbutyl O. The mixture composed of dioxane andPerbutyl O was added dropwise into the flask at 80° C. overapproximately 2 hours, followed by aging over 3 hours to obtain areaction composition containing an acrylic resin having epoxygroup-containing side chains.

The reaction composition was obtained as a solution containing 50% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 21,000, oxirane oxygen concentrationof 1.4%, an acid value of 18.5 mgKOH/g.

EXAMPLE 37 <Preparation of thermosetting resin compositions> PreparationExample 1 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

A 2-liter glass-made reaction flask equipped with an agitator,thermometer, a Dimroth condenser, a dropwise funnel, a tube for blowingnitrogen was charged with 150 parts by weight of xylene, 150 parts byweight of propyleneglycol monomethylether acetate, 3 parts by weight ofPerbutyl O (manufactured by Nihon Yushi, Ltd.), 200 parts by weight ofmethylmethacrylate, 85 parts of methacrylic acid, 100 parts by weight ofstyrene, 500 parts by weight of the 2-ethylhexyl-methacrylate, 50 partsby weight of a caprolactone-modified hydroxyethyl methacrylate (PCL FM-1manufactured by Daicel Chemical Industries, Ltd.), and 200 parts byweight of the epoxymethacrylate represented by the following chemicalformula ##STR51##

The dropwise funnel was charged with 150 parts by weight of xylene 150parts by weight of propyleneglycol monomethylether acetate, 4 parts byweight of Perbutyl O. The mixture composed of dioxane and Perbutyl O wasadded dropwise into the flask at 80° C. over approximately 2 hours,followed by aging over 3 hours to obtain a reaction compositioncontaining a methacrylic resin having epoxy group-containing sidechains.

The reaction composition was obtained as a solution containing 53% ofthe methacrylic resin having epoxy group-containing side chains having anumber average molecular weight of 6,500, oxirane oxygen concentrationof 2.2%, and an acid value of 81 mgKOH/g.

The methacrylic resin was designated as MR-1.

Preparation Examples 2-7

<Preparation of a (meth)acrylic resin having epoxy group-containing sidechains represented by the general formula (1-4)>

The same procedures were repeated as described in Preparation Example 1,except that components were changed as shown in Table 1.

                  TABLE 1                                                         ______________________________________                                                     Preparation Example                                                           2   3      4       5    6    7                                   ______________________________________                                        Mixing ratio(parts by weight)                                                 xylene        150    150    150   150  150  150                               PMEA          150    150                                                      BA                          150   150  150  150                               Perbutyl O    3      3      3     3    3    3                                 2-HEMA                                      250                               MMA           100    100    200   200  200  200                               MA            105    105                                                      styrene       150    150    100   100  100                                    g-TMPMA                     203   203  250  100                               2-EHMA                                                                        n-BMA         50     50                     100                               PCL FM-1      50     50     100   100  100  100                               EM            (2)    (3)    (4)   (5)  (6)  (7)                                             200    200    150   150  200  200                               ______________________________________                                        Mixing ratio in Dropwise funnel (parts by weight)                             xylene        150    150    150   150  150  150                               PMEA          150    150                                                      BA                          150   150  150  150                               Perbutyl O    4      4      4     4    4    4                                 Temperature (°C.)                                                                    80     80     80    80   80   80                                Dropwise addition time                                                        (approx./hour)                                                                              2      2      2     2    2    2                                 Aging time (hour)                                                                           3      3      3     3    3    3                                 Solid content (%)                                                                           52     50     47    50   58   60                                NMW           6,500  6500   7500  7500 8200 9500                              OX (%)        2.7    2.8    3.4   3.4  1.9  1.6                               AV (mgKOH/g)  103    105                                                      ______________________________________                                    

Abbreviations in the Table 1 and the epoxymethacrylates (2) to (7)employed in the Preparation Examples 2 to 7 are described below.

PMEA: propyleneglycol monomethylether acetate

BA: butyl acetate

MMA: methylmethacrylate

MA: methacrylic acid

2-EHMA: 2-ethylhexylmethacrylate

g-TMPMA: gamma-trimethoxysilylpropylmethacrylate

PCL FM-1: a caprolactone-modified hydroxyethyl methacrylate manufacturedby Daicel Chemical Industries, Ltd.

EM: epoxymethacrylate represented by the following respective formula

(2) the epoxymethacrylate obtained in Example 10

(3) the epoxymethacrylate obtained in Example 11

(4) the epoxyacrylate obtained in Example 16

(5) the epoxymethacrylate obtained in Example 15

(6) the epoxymethacrylate obtained in Example 12

(7) the epoxymethacrylate obtained in Example 12

n-BMA: n-butylmethacrylate

NMW: a number average molecular weight

OX: oxirane oxygen concentration

AV: an acid value

Application Example 1

100 parts by weight of the respective epoxymethacrylates prepared inPreparation Examples 1 and 2, and 1 part by weight of tetrabutylammoniumbromide were mixed while diluting with 1/1 mixed solvent composed ofxylene and butyl acetate to prepare clear coating compositions. Therespective compositions were coated on a plate (manufactured by NihonTest Panel, Ltd., hereinafter, the same) for electrodeposition coatingwith a Barcoater, followed by baking at 140°C. for 30 minutes to prepareCoating Layers 1 and 2.

Application Example 2

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 3 and 1 part by weight of tetraphenylphosphonium chloride weremixed while diluting with 1/1 mixed solvent composed of xylene and butylacetate to prepare a clear coating composition. The composition wascoated on a plate for electrodeposition coating with a Barcoater,followed by baking at 140° C. for 30 minutes to prepare Coating Layer 3.

Application Example 3

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 4 and 2 part by weight of tris(n-propylacetoacetate)aluminumwere mixed while diluting with 20 parts by weight of a purified3,4-epoxycyclohexyl-3,4-cyclohexanecarboxylate (Celloxide 2021Pmanufactured by Daicel Chemical Industries, Ltd.) to prepare a clearcoating composition. The composition was coated on a plate forelectrodeposition coating with a Barcoater, followed by baking at 85° C.for 30 minutes to prepare Coating Layer 4.

Application Example 4

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 5 and 2 part by weight of tris(n-propylacetoacetate) zirconiumwere mixed while diluting with 20 parts by weight of a purified3,4-epoxycyclohexyl-3,4-cyclohexanecarboxylate (Celloxide 2021Pmanufactured by Daicel Chemical Industries, Ltd.) to prepare a clearcoating composition. The composition was coated on a plate forelectrodeposition coating with a barcoater, followed by baking at 85° C.for 30 minutes to prepare Coating Layer 5.

Application Example 5

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 6 and 2 part by weight of tris(acetylacetonate)aluminum weremixed while diluting with 20 parts by weight of a purified3,4-epoxycyclohexyl-3,4-cyclohexanecarboxylate (Celloxide 2021Pmanufactured by Daicel Chemical Industries, Ltd.) to prepare a clearcoating composition. The composition was coated on a plate forelectrodeposition coating with a barcoater, followed by baking at 85° C.for 30 minutes to prepare Coating Layer 6.

Application Example 6

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 7 and 0.1 part by weight of phosphoric acid were mixed whilediluting with 1/1 solution composed of xylene and butyl acetate toprepare a clear coating composition. The composition was coated on aplate for electrodeposition coating with a barcoater, followed by bakingat 85° C. for 60 minutes to prepare Coating Layer 7.

Application Example 7

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 7 and 2 part by weight of phosphoric acid-2-ethylhexyl weremixed while diluting with 1/1 solution composed of xylene and butylacetate to prepare a clear coating composition. The composition wascoated on a plate for electrodeposition coating with a Barcoater,followed by baking at 85° C. for 60 minutes to prepare Coating Layer 8.

Application Example 8

100 parts by weight of the epoxymethacrylate prepared in PreparationExample 7 and 0.1 part by weight of phosphoric acid were mixed whilediluting with 20 parts by weight of a purified3,4-epoxycyclohexyl-3,4-cyclohexanecarboxylate (Celloxide 2021Pmanufactured by Daicel Chemical Industries, Ltd.) to prepare a clearcoating composition. The composition was coated on a plate forelectrodeposition coating with a barcoater, followed by baking at 85° C.for 60 minutes to prepare Coating Layer 9.

<Evaluation of Coating Layer>

There were evaluated properties in relation to the Coating Layers 1 to 9obtained in Application Examples 1 to 8. The results are shown in Table2.

Coating Stability: Clear coating composition prepared was placed at aroom temperature for 10 days, and then the presence or absence ofgelation and increase of viscosity was observed.

Gel Fraction: Cured coating layer was stripped from a glass plate, andthen was extracted by acetone with a Soxhlet extractor for 5 hours toweigh the residue.

Impact Strength: It was measured with a Dupon't Impact Strength testerequipped with 500 g weight.

Scratch Resistance: Cleanser (New Homing Cleanser manufactured by Kao,Ltd.) was coated on a cloth (2 cm×2 cm), and coating layer was givenabrasion under the load of 500 g, and retention ratio of 20° gloss wasmeasured after 20 cycles abrasions.

Weatherability: Irradiation (for 15 minutes) at 40° to 70° C. andcooling (for 15 minutes) was repeated for 2000 hours with a QUV testingequipment, and then deterioration degree of the coating layer wasvisually observed.

                                      TABLE 2                                     __________________________________________________________________________    Coating Layer No.                                                                      1   2  3  4   5  6  7   8  9                                         __________________________________________________________________________    Coating stability                                                                      G   G  G  G   G  G  G   G  G                                         Gel fraction (%)                                                                       99  98 97 97  96 98 99  97 96                                        Impact strength                                                                        50< 50<                                                                              50<                                                                              50< 50<                                                                              50<                                                                              50< 50<                                                                              50<                                       Pencil hardness                                                                        F   F  H  H   H  H  F   F  H                                         Scratch resistance                                                                     85  80 83 89  90 88 82  85 90                                        Weatherability                                                                         G   G  G  G   G  G  G   G  G                                         __________________________________________________________________________     In the Table 2, abbreviation G means "good".                             

The thermosetting resin composition of the present invention can quicklycure at low temperatures, and can provide excellent properties.

Accordingly, it can be preferably employed for coatings, adhesives, andinks, etc. Furthermore, scratch resistance in the coating layer isexcellent, and it can be exceedingly preferably employed asacid-resistible coatings or coatings having weatherability for cars andconstruction materials.

Example 38 <Preparation of powder coating compositions> SynthesisExample 1 <Preparation of a (meth)acrylic resin having epoxygroup-containing side chains represented by the general formula (1-4)>

80 parts by weight of the epoxymethacrylate obtained in Example 12, 20parts by weight of methacrylic acid, and 1.5 part by weight of PerhexylZ (manufactured by Nihon Yushi, Ltd.) were added dropwise into 120 partsby weight of xylene at 150° C. to polymerize. A methacrylic resin havinga molecular weight of 2000 was obtained by removing solvents afterpolymerization.

The methacrylic resin was designated as A-1.

Synthesis Examples 2 to 9

The same copolymerizations were repeated as in Synthesis Example 1except that copolymerizations were carried out in a mixing ratio ofepoxy acrylates, copolymerizable monomers, initiators, and solvents andat the conditions as shown in Table 3 to obtain methacrylic resins.

Molecular weight of the epoxy acrylates obtained is also shown in Table3.

                  TABLE 3                                                         ______________________________________                                               Synthesis Example                                                             2    3      4      5    6    7    8    9                               ______________________________________                                        Mixing ratio (parts by weight)                                                EM       (2)    (3)    (4)  (5)  (6)  (7)  (8)  (9)                                    80     80     80   80   60   50   45   80                            MMA      20     20     20   20   20   30   30   30                            Perhexyl Z                                                                             1.5    1.5    1.5  1.5  1.5  1.5  1.5  1.5                           xylene   120    120    120  120  120  120  120  120                           (150° C.)                                                              MW       1800   1700   2500 2400 2000 2200 2600 2500                          Designated No. of Methacrylic resin obtained                                         A-2  A-3    A-4    A-5  A-6  A-7  A-8  A-9                             ______________________________________                                    

In the Table 3, respective abbreviations and the epoxymethacrylates (2)to (10) employed in the Synthesis Examples 2 to 10 are as follows.

EM: Epoxy methacrylate

(2) the epoxymethacrylate obtained in Example 10

(3) the epoxymethacrylate obtained in Example 11

(4) the epoxymethacrylate obtained in Example 16

(5) the epoxymethacrylate obtained in Example 15

(6) the epoxymethacrylate obtained in Example 12

(7) the epoxymethacrylate obtained in Example 12

MMA: Methyl methacrylate

GMA: Glycidyl methacrylate

ST: Styrene

MW: Molecular weight

Synthesis Example 10 <Preparation of a methacrylic resin using glycidylmethacrylate>

50 parts by weight of the glycidylmethacrylate, 20 parts by weight ofmethacrylic acid, 20 parts by weight of styrene, and 1.5 part by weightof Perhexyl Z (manufactured by Nihon Yushi, Ltd.) were added dropwiseinto 120 parts by weight of xylene at 150° C. to polymerize. Amethacrylic resin having a molecular weight of 2500 which is aconventional methacrylic resin was obtained by removing solvents afterpolymerization. The methacrylic resin was designated as A-10.

Synthesis Example 11 <Preparation of a carboxyl-terminated polyesterresin>

A reaction vessel equipped with an agitator, a tube for blowingnitrogen, a tube for removing low-boiling-point ingredients was chargedwith 1023 parts by weight of neopentylglycol, 950 parts by weight ofdimethylterephthalate, 0.5 part by weight of zinc acetate, followed byraising temperature to 220° C. over 10 hours while removing methanol.

Successively, there were charged 33 parts by weight of adipic acid, 687parts by weight of terephthalic acid, and 1 part of dimethyltin oxide,followed by allowing to react at 180° C. for 8 hours, and raising thetemperature to 240° C. over 3 hours to allow to react for 2 hours.

Successively, reaction product was allowed to cool to 180° C., followedby adding 165 parts by weight of trimellitic anhydride to obtain acarboxyl-terminated polyester resin having an acid value of 34 mgKOH/g,a molecular weight of 2800, and a softening point of 118° C.

The polyester resin was designated by A-11.

Application Example 9

There were mixed 500 parts by weight of the methacrylic resin A-1, 270parts by weight of dodecanedicarboxylic acid, 450 parts by weight oftitanium oxide, and 1 part of "Modaflow" which is a fluidity modifier(manufactured by Monsanto, Ltd.) to prepare a powder coating compositionby kneading with an extruder, cooling, crushing, and classifying.

The powder coating composition was coated on a zinc-plated steel platewith an electrostatic coating machine, and then baked at 180° C. for 20minutes to prepare coating layer for measuring properties.

Application Examples 10 to 21

The same procedures were repeated as described in Application Example 9,except that components for mixing were changed as shown in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                  Application Example                                                           10 11 12 13 14 15 16 17 18 19 20 21                             __________________________________________________________________________    Acrylic resin (parts by weight)                                               A-1                                   100                                     A-2           500                                                             A-3              500                                                          A-4                 500                                                       A-5                    500                                                    A-6                       500   100                                           A-7                          500      100                                     A-8                             500         100                               A-9                                500                                        Curing agent (parts by weight)                                                dodecanedicarboxylic acid                                                                   270                                                                              270                                                                              405                                                                              200                                                                              160                                                                              170                                                                              225                                                                              160                                        A-11                                  620                                                                              465                                                                              485                                                                              655                            Equivalent ratio (Epoxy/COOH)                                                               1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                            pigment (titanium oxide/part by                                                             450                                                                              450                                                                              525                                                                              420                                                                              400                                                                              400                                                                              435                                                                              460                                                                              430                                                                              339                                                                              351                                                                              453                            weight)                                                                       __________________________________________________________________________

Comparative Application Examples 1 and 2

There were mixed 500 parts by weight of the methacrylic resin A-10obtained in Synthetic Example 10, 202 parts by weight ofdodecanedicarboxylic acid, 420 parts by weight of titanium oxide, and 1part of "Modaflow" which is a fluidity modifier (manufactured byMonsanto, Ltd.) to prepare a powder coating composition by kneading withan extruder, cooling, crushing, and classifying.

The powder coating composition was coated on a zinc-plated steel platewith an electrostatic coating machine, and then baked at 180° C. for 20minutes to prepare coating layer for measuring properties.

The components for mixing are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                                             Comparative                                                                   Example                                                                       1    2                                                   ______________________________________                                        Acrylic resin (parts by weight)                                               A-10                   500    100                                             Curing agent (parts by weight)                                                dodecanedicarboxylic acid                                                                            202                                                    A-11                          580                                             Equivalent ratio (Epoxy/COOH)                                                                        1.0    1.0                                             pigment (titanium oxide/part by weight)                                                              420    408                                             ______________________________________                                    

                  TABLE 6-1                                                       ______________________________________                                               Example                                                                       1    2      3      4    5    6    7    8                               ______________________________________                                        Smoothness                                                                             ◯                                                                        ◯                                                                        ◯                                                                      ◯                                                                      ◯                                                                      ◯                                                                      ◯                                                                      ◯                 Gloss (60°)                                                                     94     91     92   95   93   92   91   92                            Erichsen (mm)                                                                          >7     >7     >7   >7   >7   >7   >7   >7                            Pencil hardness                                                                        F      HB     HB   H    HB   F    HB   F                             Impact strength                                                                        50     50     50   50   50   50   50   50                            (cm)                                                                          Clinging ability                                                                       100    100    100  100  100  100  100  100                           (/100)                                                                        Solvent  ◯                                                                        ◯                                                                        ◯                                                                      ◯                                                                      ◯                                                                      ◯                                                                      ◯                                                                      ◯                 resistance                                                                    Weatherability                                                                         90     88     87   90   90   88   89   90                            (retention ratio                                                              % of 60°                                                               Gloss)                                                                        ______________________________________                                    

                  TABLE 6-2                                                       ______________________________________                                                                   Comp.                                                        Example          Example                                                      9    10     11     12   13   1    2                                 ______________________________________                                        Smoothness  ◯                                                                        ◯                                                                        ◯                                                                      ◯                                                                      ◯                                                                      X    X                               Gloss (60°)                                                                        93     90     89   90   91   --   --                              Erichsen (mm)                                                                             >7     >7     >7   >7   >7   >7   >7                              Pencil hardness                                                                           F      F      F    HB   HB   F    F                               Impact strength (cm)                                                                      50     50     50   50   50   10   10                              Anti-strippability                                                                        100    100    100  100  100  80   75                              (/100)                                                                        Solvent resistance                                                                        ◯                                                                        ◯                                                                        ◯                                                                      ◯                                                                      ◯                                                                      ◯                                                                      Δ                         Weatherability                                                                            85     86     88   84   85   69   58                              (retention                                                                    ratio % of 60° Gloss)                                                  ______________________________________                                    

Properties of coating layers were measured according to the followingrespective standards.

(a) Smoothness: Smoothness of cured coating layer was visually

measured (◯: good, Δ: slightly poor, X: poor).

(b) Gloss (60°): There was measured reflection ratio (%) by an angle ofincidence and an angle of reflection at the angle of 60° according toJIS K-5400-1991 7.6.

(c) Erichsen (mm): A steel ball was pushed from the back surface of testpiece according to JIS K-5400-1991 8.2.1. to deform the test piece.There was compared the moved length of the ball where cracks or peelingare caused in the coating layer.

(d) Pencil hardness: Scratch test with pencil was according to JIS

K-5400-1991 8.4.2. Results were visually evaluated.

(e) Impact strength (cm): In a circumstance at 25° C., a punched piecehaving the diameter of 1/2 inch phi was employed at the conditions inwhich the coated surface was faced upwardly and a weight having 1kg wasdropped from various height.

Results were evaluated by comparing maximum height not fractured.

(f) Anti-strippability: Coating layer was cut at interval of 1 mm×1 mmsquare according to JIS K-5400-1991 7.6. Successively, a test forpeeling was tried thrice by sticking tape to compare anti-strippability.

(g) Solvent resistance: Rubbing test (100 cycles) was carried out withxylene, and conditions of the coating layer were compared by visualobservation

(◯: good, Δ: slightly poor, X: poor).

(h) Weatherability (retention ratio % of 60° Gloss): There was comparedretention ratio of 60° C. Gloss after irradiated for 2000 hours with aSunshine Weather-O-Meter.

In the powder coating composition of the present invention, kneading canbe sufficiently carried out by mixing the methacrylic resins preparedusing the epoxy(meth)acrylates represented by general formula (1-2)having the epoxy groups having a mild reactivity with carboxylic group.

Furthermore, a melt viscosity of coating layer in baking is moderate.

Still further, in the case when a carboxyl-terminated polyester resin isemployed as a curing agent, compatibility between the methacrylic resinand the polyester resin is exceedingly excellent, resulting in beingcapable of providing coating layers having excellent properties.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. An epoxy(meth)acrylate represented by the formula(1-2)

    CH.sub.2 ═CR.sup.1 --COOCR.sup.a' R.sup.b' R.sup.c'    ( 1-2)

wherein R¹ is a hydrogen or a methyl group, R^(a'), R^(b'), and R^(c')are each independently a hydrogen or a substituted group represented bygeneral formula (2-2) ##STR52## at least one of R^(a'), R^(b'), andR^(c') is not hydrogen, R², R⁶, R⁷, and R¹⁰ are each independentlyhydrogen or an alkyl group having a carbon number of 1 to 10, R³ isindependently hydrogen, or an alkyl, alkenyl or epoxy group having acarbon number of 1 to 10, R⁴, R⁵, R8 and R⁹ are each independentlyhydrogen or an alkyl group having a carbon number of 1 to 5, k is aninteger of 0 to 30, l is an integer of 0 to 5, m is an integer of 0 to30, and n is an integer of 1 to 5 wherein the compound of formula (1-2)contains at least two epoxy groups.
 2. An epoxy(meth)acrylate accordingto claim 1, wherein k is 0, l is 0, m is 6, said R⁶, R⁷, R⁸, R⁹, and R¹⁰are each a hydrogen, and n is
 1. 3. An epoxy(meth)acrylate according toclaim 1, wherein k is 0, l is 0, m is 2, said R⁶, R7, R⁹, and R¹⁰ areeach a hydrogen, said R⁸ is a methyl group, and n is
 1. 4. Anepoxy(meth)acrylate according to claim 1, wherein k is 0, l is 0, m is1, said R⁶, R⁷, and R⁸ are each a hydrogen, and said R⁹ and R¹⁰ are eacha methyl group, and n is
 1. 5. An epoxy(meth)acrylate according to claim1, wherein k is 1, l is 1, m is 3, said R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹,and R¹⁰ are each a hydrogen, and n is
 1. 6. An epoxy(meth)acrylateaccording to claim 1, wherein k is 1, l is 0, m is 3, R³ is an epoxygroup, said R², R⁶, R⁷, R⁸, R⁹, and R¹⁰ are each a hydrogen, and n is 1.7. A process for the preparation of an epoxy(meth)acrylate of claim 1which comprises epoxidizing a (meth)acrylate of the formula (1-1)

    CH.sub.2 ═CR.sup.1 --COOCR.sup.a R.sup.b R.sup.c       ( 1-1)

wherein R¹ is a hydrogen or a methyl group, R^(a), R^(b), and R^(c) areeach independently a hydrogen or a substituted group represented bygeneral formula (2-1)

    --(CR.sup.2 R.sup.3).sub.k --(CR.sup.4 ═CR.sup.5).sub.l --(CR.sup.6 R.sup.7).sub.m --(CR.sup.8 ═CR.sup.9).sub.n --R.sup.10( 2-1)

at least one of R^(a), R^(b), and R^(c) is not hydrogen, R², R⁶, R⁷, andR¹⁰ are each independently hydrogen or an alkyl group having a carbonnumber of 1 to 10, R³ is independently hydrogen, or an alkyl, alkenyl orepoxy group having a carbon number of 1 to 10, R⁴, R⁵, R8 and R⁹ areeach independently hydrogen or an alkyl group having a carbon number of1 to 5, k is an integer of 0 to 30, l is an integer of 0 to 5, m is aninteger of 0 to 30, and n is an integer of 1 to 5.